diff --git a/src/lib.rs b/src/lib.rs
index 82c0385e..c0a28fcb 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -227,7 +227,6 @@ extern "C" {
     pub fn fputs(s: *const c_char, stream: *mut FILE) -> c_int;
     pub fn puts(s: *const c_char) -> c_int;
     pub fn ungetc(c: c_int, stream: *mut FILE) -> c_int;
-    pub fn getline (lineptr: *mut *mut c_char, n: *mut size_t, stream: *mut FILE) -> ssize_t;
     pub fn fread(ptr: *mut c_void, size: size_t, nobj: size_t, stream: *mut FILE) -> size_t;
     #[cfg_attr(
         all(target_os = "macos", target_arch = "x86"),
@@ -281,7 +280,6 @@ extern "C" {
     pub fn strdup(cs: *const c_char) -> *mut c_char;
     pub fn strpbrk(cs: *const c_char, ct: *const c_char) -> *mut c_char;
     pub fn strstr(cs: *const c_char, ct: *const c_char) -> *mut c_char;
-    pub fn strcasestr(cs: *const c_char, ct: *const c_char) -> *mut c_char;
     pub fn strcasecmp(s1: *const c_char, s2: *const c_char) -> c_int;
     pub fn strncasecmp(s1: *const c_char, s2: *const c_char, n: size_t) -> c_int;
     pub fn strlen(cs: *const c_char) -> size_t;
diff --git a/src/unix/bsd/apple/mod.rs b/src/unix/bsd/apple/mod.rs
index ee8108de..50bc57f4 100644
--- a/src/unix/bsd/apple/mod.rs
+++ b/src/unix/bsd/apple/mod.rs
@@ -2585,6 +2585,8 @@ extern {
         fd: ::c_int,
         newfd: ::c_int,
     ) -> ::c_int;
+
+    pub fn getline (lineptr: *mut *mut c_char, n: *mut size_t, stream: *mut FILE) -> ssize_t;
 }
 
 cfg_if! {
diff --git a/src/unix/mod.rs b/src/unix/mod.rs
index 06275a69..84c31ce7 100644
--- a/src/unix/mod.rs
+++ b/src/unix/mod.rs
@@ -947,6 +947,8 @@ extern {
     pub fn posix_openpt(flags: ::c_int) -> ::c_int;
     pub fn ptsname(fd: ::c_int) -> *mut ::c_char;
     pub fn unlockpt(fd: ::c_int) -> ::c_int;
+
+    pub fn strcasestr(cs: *const c_char, ct: *const c_char) -> *mut c_char;
 }
 
 cfg_if! {
diff --git a/src/unix/notbsd/mod.rs b/src/unix/notbsd/mod.rs
index 6e450068..d3d79244 100644
--- a/src/unix/notbsd/mod.rs
+++ b/src/unix/notbsd/mod.rs
@@ -1229,6 +1229,8 @@ extern {
                    flags: ::c_int) -> ::ssize_t;
     pub fn recvmsg(fd: ::c_int, msg: *mut ::msghdr, flags: ::c_int)
                    -> ::ssize_t;
+
+    pub fn getline (lineptr: *mut *mut c_char, n: *mut size_t, stream: *mut FILE) -> ssize_t;
 }
 
 cfg_if! {