diff --git a/Cargo.lock b/Cargo.lock
index 4417c25abcb..6efce4297dc 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -835,7 +835,7 @@ dependencies = [
  "proc-macro2 0.4.24 (registry+https://github.com/rust-lang/crates.io-index)",
  "quote 0.6.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "syn 0.15.22 (registry+https://github.com/rust-lang/crates.io-index)",
- "synstructure 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "synstructure 0.10.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -2849,7 +2849,7 @@ dependencies = [
  "proc-macro2 0.4.24 (registry+https://github.com/rust-lang/crates.io-index)",
  "quote 0.6.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "syn 0.15.22 (registry+https://github.com/rust-lang/crates.io-index)",
- "synstructure 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "synstructure 0.10.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -3385,7 +3385,7 @@ dependencies = [
 
 [[package]]
 name = "synstructure"
-version = "0.10.1"
+version = "0.10.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "proc-macro2 0.4.24 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4306,7 +4306,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum syn 0.11.11 (registry+https://github.com/rust-lang/crates.io-index)" = "d3b891b9015c88c576343b9b3e41c2c11a51c219ef067b264bd9c8aa9b441dad"
 "checksum syn 0.15.22 (registry+https://github.com/rust-lang/crates.io-index)" = "ae8b29eb5210bc5cf63ed6149cbf9adfc82ac0be023d8735c176ee74a2db4da7"
 "checksum synom 0.11.3 (registry+https://github.com/rust-lang/crates.io-index)" = "a393066ed9010ebaed60b9eafa373d4b1baac186dd7e008555b0f702b51945b6"
-"checksum synstructure 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)" = "73687139bf99285483c96ac0add482c3776528beac1d97d444f6e91f203a2015"
+"checksum synstructure 0.10.2 (registry+https://github.com/rust-lang/crates.io-index)" = "02353edf96d6e4dc81aea2d8490a7e9db177bf8acb0e951c24940bf866cb313f"
 "checksum tar 0.4.20 (registry+https://github.com/rust-lang/crates.io-index)" = "a303ba60a099fcd2aaa646b14d2724591a96a75283e4b7ed3d1a1658909d9ae2"
 "checksum tempfile 3.0.5 (registry+https://github.com/rust-lang/crates.io-index)" = "7e91405c14320e5c79b3d148e1c86f40749a36e490642202a31689cb1a3452b2"
 "checksum tendril 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "9de21546595a0873061940d994bbbc5c35f024ae4fd61ec5c5b159115684f508"
diff --git a/src/bootstrap/doc.rs b/src/bootstrap/doc.rs
index 9c3a17bff6b..5605ec34083 100644
--- a/src/bootstrap/doc.rs
+++ b/src/bootstrap/doc.rs
@@ -728,7 +728,7 @@ impl Step for Rustc {
 
         // Build cargo command.
         let mut cargo = builder.cargo(compiler, Mode::Rustc, target, "doc");
-        cargo.env("RUSTDOCFLAGS", "--document-private-items");
+        cargo.env("RUSTDOCFLAGS", "--document-private-items --passes strip-hidden");
         compile::rustc_cargo(builder, &mut cargo);
 
         // Only include compiler crates, no dependencies of those, such as `libc`.
diff --git a/src/librustc_macros/Cargo.toml b/src/librustc_macros/Cargo.toml
index 6e32a53c364..f989ebc6dfd 100644
--- a/src/librustc_macros/Cargo.toml
+++ b/src/librustc_macros/Cargo.toml
@@ -8,7 +8,7 @@ edition = "2018"
 proc-macro = true
 
 [dependencies]
-synstructure = "0.10.1"
+synstructure = "0.10.2"
 syn = { version = "0.15.22", features = ["full"] }
 proc-macro2 = "0.4.24"
 quote = "0.6.10"