diff --git a/src/librustc_typeck/check/demand.rs b/src/librustc_typeck/check/demand.rs
index 369bb183bcd..2f890d4dabb 100644
--- a/src/librustc_typeck/check/demand.rs
+++ b/src/librustc_typeck/check/demand.rs
@@ -753,8 +753,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
             match (&expected_ty.kind, &checked_ty.kind) {
                 (&ty::Int(ref exp), &ty::Int(ref found)) => {
-                    let is_fallible = match (found.bit_width(), exp.bit_width()) {
-                        (Some(found), Some(exp)) if found > exp => true,
+                    let is_fallible = match (exp.bit_width(), found.bit_width()) {
+                        (Some(exp), Some(found)) if exp < found => true,
+                        (None, Some(8 | 16)) => false,
                         (None, _) | (_, None) => true,
                         _ => false,
                     };
@@ -762,8 +763,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     true
                 }
                 (&ty::Uint(ref exp), &ty::Uint(ref found)) => {
-                    let is_fallible = match (found.bit_width(), exp.bit_width()) {
-                        (Some(found), Some(exp)) if found > exp => true,
+                    let is_fallible = match (exp.bit_width(), found.bit_width()) {
+                        (Some(exp), Some(found)) if exp < found => true,
+                        (None, Some(8 | 16)) => false,
                         (None, _) | (_, None) => true,
                         _ => false,
                     };
diff --git a/src/test/ui/integer-literal-suffix-inference.rs b/src/test/ui/integer-literal-suffix-inference.rs
index 3f4bedc4c22..c320f2bb7b4 100644
--- a/src/test/ui/integer-literal-suffix-inference.rs
+++ b/src/test/ui/integer-literal-suffix-inference.rs
@@ -16,6 +16,7 @@ fn main() {
     fn id_i16(n: i16) -> i16 { n }
     fn id_i32(n: i32) -> i32 { n }
     fn id_i64(n: i64) -> i64 { n }
+    fn id_isize(n: isize) -> isize { n }
 
     // the smallest values that need these types
     let b8: u8 = 16;
@@ -27,6 +28,11 @@ fn main() {
     fn id_u16(n: u16) -> u16 { n }
     fn id_u32(n: u32) -> u32 { n }
     fn id_u64(n: u64) -> u64 { n }
+    fn id_usize(n: usize) -> usize { n }
+
+    // Values for testing *size
+    let asize: isize = 1;
+    let bsize: usize = 3;
 
     id_i8(a8); // ok
     id_i8(a16);
@@ -38,6 +44,9 @@ fn main() {
     id_i8(a64);
     //~^ ERROR mismatched types
     //~| expected `i8`, found `i64`
+    id_i8(asize);
+    //~^ ERROR mismatched types
+    //~| expected `i8`, found `isize`
 
     id_i16(a8);
     //~^ ERROR mismatched types
@@ -49,6 +58,9 @@ fn main() {
     id_i16(a64);
     //~^ ERROR mismatched types
     //~| expected `i16`, found `i64`
+    id_i16(asize);
+    //~^ ERROR mismatched types
+    //~| expected `i16`, found `isize`
 
     id_i32(a8);
     //~^ ERROR mismatched types
@@ -60,6 +72,9 @@ fn main() {
     id_i32(a64);
     //~^ ERROR mismatched types
     //~| expected `i32`, found `i64`
+    id_i32(asize);
+    //~^ ERROR mismatched types
+    //~| expected `i32`, found `isize`
 
     id_i64(a8);
     //~^ ERROR mismatched types
@@ -71,6 +86,23 @@ fn main() {
     //~^ ERROR mismatched types
     //~| expected `i64`, found `i32`
     id_i64(a64); // ok
+    id_i64(asize);
+    //~^ ERROR mismatched types
+    //~| expected `i64`, found `isize`
+
+    id_isize(a8);
+    //~^ ERROR mismatched types
+    //~| expected `isize`, found `i8`
+    id_isize(a16);
+    //~^ ERROR mismatched types
+    //~| expected `isize`, found `i16`
+    id_isize(a32);
+    //~^ ERROR mismatched types
+    //~| expected `isize`, found `i32`
+    id_isize(a64);
+    //~^ ERROR mismatched types
+    //~| expected `isize`, found `i64`
+    id_isize(asize); //ok
 
     id_i8(c8); // ok
     id_i8(c16);
@@ -126,6 +158,9 @@ fn main() {
     id_u8(b64);
     //~^ ERROR mismatched types
     //~| expected `u8`, found `u64`
+    id_u8(bsize);
+    //~^ ERROR mismatched types
+    //~| expected `u8`, found `usize`
 
     id_u16(b8);
     //~^ ERROR mismatched types
@@ -137,6 +172,9 @@ fn main() {
     id_u16(b64);
     //~^ ERROR mismatched types
     //~| expected `u16`, found `u64`
+    id_u16(bsize);
+    //~^ ERROR mismatched types
+    //~| expected `u16`, found `usize`
 
     id_u32(b8);
     //~^ ERROR mismatched types
@@ -148,6 +186,9 @@ fn main() {
     id_u32(b64);
     //~^ ERROR mismatched types
     //~| expected `u32`, found `u64`
+    id_u32(bsize);
+    //~^ ERROR mismatched types
+    //~| expected `u32`, found `usize`
 
     id_u64(b8);
     //~^ ERROR mismatched types
@@ -159,4 +200,21 @@ fn main() {
     //~^ ERROR mismatched types
     //~| expected `u64`, found `u32`
     id_u64(b64); // ok
+    id_u64(bsize);
+    //~^ ERROR mismatched types
+    //~| expected `u64`, found `usize`
+
+    id_usize(b8);
+    //~^ ERROR mismatched types
+    //~| expected `usize`, found `u8`
+    id_usize(b16);
+    //~^ ERROR mismatched types
+    //~| expected `usize`, found `u16`
+    id_usize(b32);
+    //~^ ERROR mismatched types
+    //~| expected `usize`, found `u32`
+    id_usize(b64);
+    //~^ ERROR mismatched types
+    //~| expected `usize`, found `u64`
+    id_usize(bsize); //ok
 }
diff --git a/src/test/ui/integer-literal-suffix-inference.stderr b/src/test/ui/integer-literal-suffix-inference.stderr
index a34f0645c6b..b8502768e1d 100644
--- a/src/test/ui/integer-literal-suffix-inference.stderr
+++ b/src/test/ui/integer-literal-suffix-inference.stderr
@@ -1,5 +1,5 @@
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:32:11
+  --> $DIR/integer-literal-suffix-inference.rs:38:11
    |
 LL |     id_i8(a16);
    |           ^^^ expected `i8`, found `i16`
@@ -10,7 +10,7 @@ LL |     id_i8(a16.try_into().unwrap());
    |           ^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:35:11
+  --> $DIR/integer-literal-suffix-inference.rs:41:11
    |
 LL |     id_i8(a32);
    |           ^^^ expected `i8`, found `i32`
@@ -21,7 +21,7 @@ LL |     id_i8(a32.try_into().unwrap());
    |           ^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:38:11
+  --> $DIR/integer-literal-suffix-inference.rs:44:11
    |
 LL |     id_i8(a64);
    |           ^^^ expected `i8`, found `i64`
@@ -32,7 +32,18 @@ LL |     id_i8(a64.try_into().unwrap());
    |           ^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:42:12
+  --> $DIR/integer-literal-suffix-inference.rs:47:11
+   |
+LL |     id_i8(asize);
+   |           ^^^^^ expected `i8`, found `isize`
+   |
+help: you can convert an `isize` to `i8` and panic if the converted value wouldn't fit
+   |
+LL |     id_i8(asize.try_into().unwrap());
+   |           ^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error[E0308]: mismatched types
+  --> $DIR/integer-literal-suffix-inference.rs:51:12
    |
 LL |     id_i16(a8);
    |            ^^
@@ -41,7 +52,7 @@ LL |     id_i16(a8);
    |            help: you can convert an `i8` to `i16`: `a8.into()`
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:46:12
+  --> $DIR/integer-literal-suffix-inference.rs:55:12
    |
 LL |     id_i16(a32);
    |            ^^^ expected `i16`, found `i32`
@@ -52,7 +63,7 @@ LL |     id_i16(a32.try_into().unwrap());
    |            ^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:49:12
+  --> $DIR/integer-literal-suffix-inference.rs:58:12
    |
 LL |     id_i16(a64);
    |            ^^^ expected `i16`, found `i64`
@@ -63,7 +74,18 @@ LL |     id_i16(a64.try_into().unwrap());
    |            ^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:53:12
+  --> $DIR/integer-literal-suffix-inference.rs:61:12
+   |
+LL |     id_i16(asize);
+   |            ^^^^^ expected `i16`, found `isize`
+   |
+help: you can convert an `isize` to `i16` and panic if the converted value wouldn't fit
+   |
+LL |     id_i16(asize.try_into().unwrap());
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error[E0308]: mismatched types
+  --> $DIR/integer-literal-suffix-inference.rs:65:12
    |
 LL |     id_i32(a8);
    |            ^^
@@ -72,7 +94,7 @@ LL |     id_i32(a8);
    |            help: you can convert an `i8` to `i32`: `a8.into()`
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:56:12
+  --> $DIR/integer-literal-suffix-inference.rs:68:12
    |
 LL |     id_i32(a16);
    |            ^^^
@@ -81,7 +103,7 @@ LL |     id_i32(a16);
    |            help: you can convert an `i16` to `i32`: `a16.into()`
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:60:12
+  --> $DIR/integer-literal-suffix-inference.rs:72:12
    |
 LL |     id_i32(a64);
    |            ^^^ expected `i32`, found `i64`
@@ -92,7 +114,18 @@ LL |     id_i32(a64.try_into().unwrap());
    |            ^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:64:12
+  --> $DIR/integer-literal-suffix-inference.rs:75:12
+   |
+LL |     id_i32(asize);
+   |            ^^^^^ expected `i32`, found `isize`
+   |
+help: you can convert an `isize` to `i32` and panic if the converted value wouldn't fit
+   |
+LL |     id_i32(asize.try_into().unwrap());
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error[E0308]: mismatched types
+  --> $DIR/integer-literal-suffix-inference.rs:79:12
    |
 LL |     id_i64(a8);
    |            ^^
@@ -101,7 +134,7 @@ LL |     id_i64(a8);
    |            help: you can convert an `i8` to `i64`: `a8.into()`
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:67:12
+  --> $DIR/integer-literal-suffix-inference.rs:82:12
    |
 LL |     id_i64(a16);
    |            ^^^
@@ -110,7 +143,7 @@ LL |     id_i64(a16);
    |            help: you can convert an `i16` to `i64`: `a16.into()`
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:70:12
+  --> $DIR/integer-literal-suffix-inference.rs:85:12
    |
 LL |     id_i64(a32);
    |            ^^^
@@ -119,7 +152,58 @@ LL |     id_i64(a32);
    |            help: you can convert an `i32` to `i64`: `a32.into()`
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:76:11
+  --> $DIR/integer-literal-suffix-inference.rs:89:12
+   |
+LL |     id_i64(asize);
+   |            ^^^^^ expected `i64`, found `isize`
+   |
+help: you can convert an `isize` to `i64` and panic if the converted value wouldn't fit
+   |
+LL |     id_i64(asize.try_into().unwrap());
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error[E0308]: mismatched types
+  --> $DIR/integer-literal-suffix-inference.rs:93:14
+   |
+LL |     id_isize(a8);
+   |              ^^
+   |              |
+   |              expected `isize`, found `i8`
+   |              help: you can convert an `i8` to `isize`: `a8.into()`
+
+error[E0308]: mismatched types
+  --> $DIR/integer-literal-suffix-inference.rs:96:14
+   |
+LL |     id_isize(a16);
+   |              ^^^
+   |              |
+   |              expected `isize`, found `i16`
+   |              help: you can convert an `i16` to `isize`: `a16.into()`
+
+error[E0308]: mismatched types
+  --> $DIR/integer-literal-suffix-inference.rs:99:14
+   |
+LL |     id_isize(a32);
+   |              ^^^ expected `isize`, found `i32`
+   |
+help: you can convert an `i32` to `isize` and panic if the converted value wouldn't fit
+   |
+LL |     id_isize(a32.try_into().unwrap());
+   |              ^^^^^^^^^^^^^^^^^^^^^^^
+
+error[E0308]: mismatched types
+  --> $DIR/integer-literal-suffix-inference.rs:102:14
+   |
+LL |     id_isize(a64);
+   |              ^^^ expected `isize`, found `i64`
+   |
+help: you can convert an `i64` to `isize` and panic if the converted value wouldn't fit
+   |
+LL |     id_isize(a64.try_into().unwrap());
+   |              ^^^^^^^^^^^^^^^^^^^^^^^
+
+error[E0308]: mismatched types
+  --> $DIR/integer-literal-suffix-inference.rs:108:11
    |
 LL |     id_i8(c16);
    |           ^^^ expected `i8`, found `i16`
@@ -130,7 +214,7 @@ LL |     id_i8(c16.try_into().unwrap());
    |           ^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:79:11
+  --> $DIR/integer-literal-suffix-inference.rs:111:11
    |
 LL |     id_i8(c32);
    |           ^^^ expected `i8`, found `i32`
@@ -141,7 +225,7 @@ LL |     id_i8(c32.try_into().unwrap());
    |           ^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:82:11
+  --> $DIR/integer-literal-suffix-inference.rs:114:11
    |
 LL |     id_i8(c64);
    |           ^^^ expected `i8`, found `i64`
@@ -152,7 +236,7 @@ LL |     id_i8(c64.try_into().unwrap());
    |           ^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:86:12
+  --> $DIR/integer-literal-suffix-inference.rs:118:12
    |
 LL |     id_i16(c8);
    |            ^^
@@ -161,7 +245,7 @@ LL |     id_i16(c8);
    |            help: you can convert an `i8` to `i16`: `c8.into()`
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:90:12
+  --> $DIR/integer-literal-suffix-inference.rs:122:12
    |
 LL |     id_i16(c32);
    |            ^^^ expected `i16`, found `i32`
@@ -172,7 +256,7 @@ LL |     id_i16(c32.try_into().unwrap());
    |            ^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:93:12
+  --> $DIR/integer-literal-suffix-inference.rs:125:12
    |
 LL |     id_i16(c64);
    |            ^^^ expected `i16`, found `i64`
@@ -183,7 +267,7 @@ LL |     id_i16(c64.try_into().unwrap());
    |            ^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:97:12
+  --> $DIR/integer-literal-suffix-inference.rs:129:12
    |
 LL |     id_i32(c8);
    |            ^^
@@ -192,7 +276,7 @@ LL |     id_i32(c8);
    |            help: you can convert an `i8` to `i32`: `c8.into()`
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:100:12
+  --> $DIR/integer-literal-suffix-inference.rs:132:12
    |
 LL |     id_i32(c16);
    |            ^^^
@@ -201,7 +285,7 @@ LL |     id_i32(c16);
    |            help: you can convert an `i16` to `i32`: `c16.into()`
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:104:12
+  --> $DIR/integer-literal-suffix-inference.rs:136:12
    |
 LL |     id_i32(c64);
    |            ^^^ expected `i32`, found `i64`
@@ -212,7 +296,7 @@ LL |     id_i32(c64.try_into().unwrap());
    |            ^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:108:12
+  --> $DIR/integer-literal-suffix-inference.rs:140:12
    |
 LL |     id_i64(a8);
    |            ^^
@@ -221,7 +305,7 @@ LL |     id_i64(a8);
    |            help: you can convert an `i8` to `i64`: `a8.into()`
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:111:12
+  --> $DIR/integer-literal-suffix-inference.rs:143:12
    |
 LL |     id_i64(a16);
    |            ^^^
@@ -230,7 +314,7 @@ LL |     id_i64(a16);
    |            help: you can convert an `i16` to `i64`: `a16.into()`
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:114:12
+  --> $DIR/integer-literal-suffix-inference.rs:146:12
    |
 LL |     id_i64(a32);
    |            ^^^
@@ -239,7 +323,7 @@ LL |     id_i64(a32);
    |            help: you can convert an `i32` to `i64`: `a32.into()`
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:120:11
+  --> $DIR/integer-literal-suffix-inference.rs:152:11
    |
 LL |     id_u8(b16);
    |           ^^^ expected `u8`, found `u16`
@@ -250,7 +334,7 @@ LL |     id_u8(b16.try_into().unwrap());
    |           ^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:123:11
+  --> $DIR/integer-literal-suffix-inference.rs:155:11
    |
 LL |     id_u8(b32);
    |           ^^^ expected `u8`, found `u32`
@@ -261,7 +345,7 @@ LL |     id_u8(b32.try_into().unwrap());
    |           ^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:126:11
+  --> $DIR/integer-literal-suffix-inference.rs:158:11
    |
 LL |     id_u8(b64);
    |           ^^^ expected `u8`, found `u64`
@@ -272,7 +356,18 @@ LL |     id_u8(b64.try_into().unwrap());
    |           ^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:130:12
+  --> $DIR/integer-literal-suffix-inference.rs:161:11
+   |
+LL |     id_u8(bsize);
+   |           ^^^^^ expected `u8`, found `usize`
+   |
+help: you can convert an `usize` to `u8` and panic if the converted value wouldn't fit
+   |
+LL |     id_u8(bsize.try_into().unwrap());
+   |           ^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error[E0308]: mismatched types
+  --> $DIR/integer-literal-suffix-inference.rs:165:12
    |
 LL |     id_u16(b8);
    |            ^^
@@ -281,7 +376,7 @@ LL |     id_u16(b8);
    |            help: you can convert an `u8` to `u16`: `b8.into()`
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:134:12
+  --> $DIR/integer-literal-suffix-inference.rs:169:12
    |
 LL |     id_u16(b32);
    |            ^^^ expected `u16`, found `u32`
@@ -292,7 +387,7 @@ LL |     id_u16(b32.try_into().unwrap());
    |            ^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:137:12
+  --> $DIR/integer-literal-suffix-inference.rs:172:12
    |
 LL |     id_u16(b64);
    |            ^^^ expected `u16`, found `u64`
@@ -303,7 +398,18 @@ LL |     id_u16(b64.try_into().unwrap());
    |            ^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:141:12
+  --> $DIR/integer-literal-suffix-inference.rs:175:12
+   |
+LL |     id_u16(bsize);
+   |            ^^^^^ expected `u16`, found `usize`
+   |
+help: you can convert an `usize` to `u16` and panic if the converted value wouldn't fit
+   |
+LL |     id_u16(bsize.try_into().unwrap());
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error[E0308]: mismatched types
+  --> $DIR/integer-literal-suffix-inference.rs:179:12
    |
 LL |     id_u32(b8);
    |            ^^
@@ -312,7 +418,7 @@ LL |     id_u32(b8);
    |            help: you can convert an `u8` to `u32`: `b8.into()`
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:144:12
+  --> $DIR/integer-literal-suffix-inference.rs:182:12
    |
 LL |     id_u32(b16);
    |            ^^^
@@ -321,7 +427,7 @@ LL |     id_u32(b16);
    |            help: you can convert an `u16` to `u32`: `b16.into()`
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:148:12
+  --> $DIR/integer-literal-suffix-inference.rs:186:12
    |
 LL |     id_u32(b64);
    |            ^^^ expected `u32`, found `u64`
@@ -332,7 +438,18 @@ LL |     id_u32(b64.try_into().unwrap());
    |            ^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:152:12
+  --> $DIR/integer-literal-suffix-inference.rs:189:12
+   |
+LL |     id_u32(bsize);
+   |            ^^^^^ expected `u32`, found `usize`
+   |
+help: you can convert an `usize` to `u32` and panic if the converted value wouldn't fit
+   |
+LL |     id_u32(bsize.try_into().unwrap());
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error[E0308]: mismatched types
+  --> $DIR/integer-literal-suffix-inference.rs:193:12
    |
 LL |     id_u64(b8);
    |            ^^
@@ -341,7 +458,7 @@ LL |     id_u64(b8);
    |            help: you can convert an `u8` to `u64`: `b8.into()`
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:155:12
+  --> $DIR/integer-literal-suffix-inference.rs:196:12
    |
 LL |     id_u64(b16);
    |            ^^^
@@ -350,7 +467,7 @@ LL |     id_u64(b16);
    |            help: you can convert an `u16` to `u64`: `b16.into()`
 
 error[E0308]: mismatched types
-  --> $DIR/integer-literal-suffix-inference.rs:158:12
+  --> $DIR/integer-literal-suffix-inference.rs:199:12
    |
 LL |     id_u64(b32);
    |            ^^^
@@ -358,6 +475,57 @@ LL |     id_u64(b32);
    |            expected `u64`, found `u32`
    |            help: you can convert an `u32` to `u64`: `b32.into()`
 
-error: aborting due to 36 previous errors
+error[E0308]: mismatched types
+  --> $DIR/integer-literal-suffix-inference.rs:203:12
+   |
+LL |     id_u64(bsize);
+   |            ^^^^^ expected `u64`, found `usize`
+   |
+help: you can convert an `usize` to `u64` and panic if the converted value wouldn't fit
+   |
+LL |     id_u64(bsize.try_into().unwrap());
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error[E0308]: mismatched types
+  --> $DIR/integer-literal-suffix-inference.rs:207:14
+   |
+LL |     id_usize(b8);
+   |              ^^
+   |              |
+   |              expected `usize`, found `u8`
+   |              help: you can convert an `u8` to `usize`: `b8.into()`
+
+error[E0308]: mismatched types
+  --> $DIR/integer-literal-suffix-inference.rs:210:14
+   |
+LL |     id_usize(b16);
+   |              ^^^
+   |              |
+   |              expected `usize`, found `u16`
+   |              help: you can convert an `u16` to `usize`: `b16.into()`
+
+error[E0308]: mismatched types
+  --> $DIR/integer-literal-suffix-inference.rs:213:14
+   |
+LL |     id_usize(b32);
+   |              ^^^ expected `usize`, found `u32`
+   |
+help: you can convert an `u32` to `usize` and panic if the converted value wouldn't fit
+   |
+LL |     id_usize(b32.try_into().unwrap());
+   |              ^^^^^^^^^^^^^^^^^^^^^^^
+
+error[E0308]: mismatched types
+  --> $DIR/integer-literal-suffix-inference.rs:216:14
+   |
+LL |     id_usize(b64);
+   |              ^^^ expected `usize`, found `u64`
+   |
+help: you can convert an `u64` to `usize` and panic if the converted value wouldn't fit
+   |
+LL |     id_usize(b64.try_into().unwrap());
+   |              ^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 52 previous errors
 
 For more information about this error, try `rustc --explain E0308`.
diff --git a/src/test/ui/numeric/numeric-cast.fixed b/src/test/ui/numeric/numeric-cast.fixed
index 6f78228a85d..31acdb8faf6 100644
--- a/src/test/ui/numeric/numeric-cast.fixed
+++ b/src/test/ui/numeric/numeric-cast.fixed
@@ -24,9 +24,9 @@ fn main() {
     //~^ ERROR mismatched types
     foo::<usize>(x_u32.try_into().unwrap());
     //~^ ERROR mismatched types
-    foo::<usize>(x_u16.try_into().unwrap());
+    foo::<usize>(x_u16.into());
     //~^ ERROR mismatched types
-    foo::<usize>(x_u8.try_into().unwrap());
+    foo::<usize>(x_u8.into());
     //~^ ERROR mismatched types
     foo::<usize>(x_isize.try_into().unwrap());
     //~^ ERROR mismatched types
@@ -56,9 +56,9 @@ fn main() {
     //~^ ERROR mismatched types
     foo::<isize>(x_i32.try_into().unwrap());
     //~^ ERROR mismatched types
-    foo::<isize>(x_i16.try_into().unwrap());
+    foo::<isize>(x_i16.into());
     //~^ ERROR mismatched types
-    foo::<isize>(x_i8.try_into().unwrap());
+    foo::<isize>(x_i8.into());
     //~^ ERROR mismatched types
     // foo::<isize>(x_f64);
     // foo::<isize>(x_f32);
diff --git a/src/test/ui/numeric/numeric-cast.stderr b/src/test/ui/numeric/numeric-cast.stderr
index eef40cbdbe4..ff92a86c3a7 100644
--- a/src/test/ui/numeric/numeric-cast.stderr
+++ b/src/test/ui/numeric/numeric-cast.stderr
@@ -24,23 +24,19 @@ error[E0308]: mismatched types
   --> $DIR/numeric-cast.rs:27:18
    |
 LL |     foo::<usize>(x_u16);
-   |                  ^^^^^ expected `usize`, found `u16`
-   |
-help: you can convert an `u16` to `usize` and panic if the converted value wouldn't fit
-   |
-LL |     foo::<usize>(x_u16.try_into().unwrap());
-   |                  ^^^^^^^^^^^^^^^^^^^^^^^^^
+   |                  ^^^^^
+   |                  |
+   |                  expected `usize`, found `u16`
+   |                  help: you can convert an `u16` to `usize`: `x_u16.into()`
 
 error[E0308]: mismatched types
   --> $DIR/numeric-cast.rs:29:18
    |
 LL |     foo::<usize>(x_u8);
-   |                  ^^^^ expected `usize`, found `u8`
-   |
-help: you can convert an `u8` to `usize` and panic if the converted value wouldn't fit
-   |
-LL |     foo::<usize>(x_u8.try_into().unwrap());
-   |                  ^^^^^^^^^^^^^^^^^^^^^^^^
+   |                  ^^^^
+   |                  |
+   |                  expected `usize`, found `u8`
+   |                  help: you can convert an `u8` to `usize`: `x_u8.into()`
 
 error[E0308]: mismatched types
   --> $DIR/numeric-cast.rs:31:18
@@ -178,23 +174,19 @@ error[E0308]: mismatched types
   --> $DIR/numeric-cast.rs:59:18
    |
 LL |     foo::<isize>(x_i16);
-   |                  ^^^^^ expected `isize`, found `i16`
-   |
-help: you can convert an `i16` to `isize` and panic if the converted value wouldn't fit
-   |
-LL |     foo::<isize>(x_i16.try_into().unwrap());
-   |                  ^^^^^^^^^^^^^^^^^^^^^^^^^
+   |                  ^^^^^
+   |                  |
+   |                  expected `isize`, found `i16`
+   |                  help: you can convert an `i16` to `isize`: `x_i16.into()`
 
 error[E0308]: mismatched types
   --> $DIR/numeric-cast.rs:61:18
    |
 LL |     foo::<isize>(x_i8);
-   |                  ^^^^ expected `isize`, found `i8`
-   |
-help: you can convert an `i8` to `isize` and panic if the converted value wouldn't fit
-   |
-LL |     foo::<isize>(x_i8.try_into().unwrap());
-   |                  ^^^^^^^^^^^^^^^^^^^^^^^^
+   |                  ^^^^
+   |                  |
+   |                  expected `isize`, found `i8`
+   |                  help: you can convert an `i8` to `isize`: `x_i8.into()`
 
 error[E0308]: mismatched types
   --> $DIR/numeric-cast.rs:66:16