diff --git a/library/std/src/alloc.rs b/library/std/src/alloc.rs
index 3936ed057e6..99d105a2454 100644
--- a/library/std/src/alloc.rs
+++ b/library/std/src/alloc.rs
@@ -20,11 +20,11 @@
 //!
 //! unsafe impl GlobalAlloc for MyAllocator {
 //!     unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
-//!         System.alloc(layout)
+//!         unsafe { System.alloc(layout) }
 //!     }
 //!
 //!     unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
-//!         System.dealloc(ptr, layout)
+//!         unsafe { System.dealloc(ptr, layout) }
 //!     }
 //! }
 //!
@@ -102,7 +102,7 @@ pub use alloc_crate::alloc::*;
 ///
 /// unsafe impl GlobalAlloc for Counter {
 ///     unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
-///         let ret = System.alloc(layout);
+///         let ret = unsafe { System.alloc(layout) };
 ///         if !ret.is_null() {
 ///             ALLOCATED.fetch_add(layout.size(), Relaxed);
 ///         }
@@ -110,7 +110,7 @@ pub use alloc_crate::alloc::*;
 ///     }
 ///
 ///     unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
-///         System.dealloc(ptr, layout);
+///         unsafe { System.dealloc(ptr, layout); }
 ///         ALLOCATED.fetch_sub(layout.size(), Relaxed);
 ///     }
 /// }
diff --git a/library/std/src/sys/pal/teeos/thread.rs b/library/std/src/sys/pal/teeos/thread.rs
index c779c5f3ed8..e3b4908f858 100644
--- a/library/std/src/sys/pal/teeos/thread.rs
+++ b/library/std/src/sys/pal/teeos/thread.rs
@@ -56,7 +56,7 @@ impl Thread {
             }
         };
 
-        let ret = libc::pthread_create(&mut native, &attr, thread_start, p as *mut _);
+        let ret = unsafe { libc::pthread_create(&mut native, &attr, thread_start, p as *mut _) };
         // Note: if the thread creation fails and this assert fails, then p will
         // be leaked. However, an alternative design could cause double-free
         // which is clearly worse.