diff --git a/src/libstd/sys/cloudabi/thread.rs b/src/libstd/sys/cloudabi/thread.rs
index 78a3b82546e3..a22d9053b696 100644
--- a/src/libstd/sys/cloudabi/thread.rs
+++ b/src/libstd/sys/cloudabi/thread.rs
@@ -118,6 +118,7 @@ pub mod guard {
     pub unsafe fn init() -> Option<Guard> {
         None
     }
+    pub unsafe fn deinit() {}
 }
 
 fn min_stack_size(_: *const libc::pthread_attr_t) -> usize {
diff --git a/src/libstd/sys/redox/thread.rs b/src/libstd/sys/redox/thread.rs
index c4719a94c7e9..f20350269b7c 100644
--- a/src/libstd/sys/redox/thread.rs
+++ b/src/libstd/sys/redox/thread.rs
@@ -91,4 +91,5 @@ pub mod guard {
     pub type Guard = !;
     pub unsafe fn current() -> Option<Guard> { None }
     pub unsafe fn init() -> Option<Guard> { None }
+    pub unsafe fn deinit() {}
 }
diff --git a/src/libstd/sys/unix/thread.rs b/src/libstd/sys/unix/thread.rs
index 4364089a1818..b9ec0d4a4033 100644
--- a/src/libstd/sys/unix/thread.rs
+++ b/src/libstd/sys/unix/thread.rs
@@ -209,6 +209,7 @@ pub mod guard {
     pub type Guard = Range<usize>;
     pub unsafe fn current() -> Option<Guard> { None }
     pub unsafe fn init() -> Option<Guard> { None }
+    pub unsafe fn deinit() {}
 }
 
 
diff --git a/src/libstd/sys/wasm/thread.rs b/src/libstd/sys/wasm/thread.rs
index 6a066509b492..7345843b975e 100644
--- a/src/libstd/sys/wasm/thread.rs
+++ b/src/libstd/sys/wasm/thread.rs
@@ -46,4 +46,5 @@ pub mod guard {
     pub type Guard = !;
     pub unsafe fn current() -> Option<Guard> { None }
     pub unsafe fn init() -> Option<Guard> { None }
+    pub unsafe fn deinit() {}
 }
diff --git a/src/libstd/sys/windows/thread.rs b/src/libstd/sys/windows/thread.rs
index 43abfbb1f645..4b3d1b586b57 100644
--- a/src/libstd/sys/windows/thread.rs
+++ b/src/libstd/sys/windows/thread.rs
@@ -96,4 +96,5 @@ pub mod guard {
     pub type Guard = !;
     pub unsafe fn current() -> Option<Guard> { None }
     pub unsafe fn init() -> Option<Guard> { None }
+    pub unsafe fn deinit() {}
 }