diff --git a/src/librustc_data_structures/sync.rs b/src/librustc_data_structures/sync.rs
index 184ef1369761..0f534f0adec4 100644
--- a/src/librustc_data_structures/sync.rs
+++ b/src/librustc_data_structures/sync.rs
@@ -388,6 +388,18 @@ impl<T> RwLock<T> {
         f(&*self.read())
     }
 
+    #[cfg(not(parallel_queries))]
+    #[inline(always)]
+    pub fn try_write(&self) -> Result<WriteGuard<T>, ()> {
+        self.0.try_borrow_mut().map_err(|_| ())
+    }
+
+    #[cfg(parallel_queries)]
+    #[inline(always)]
+    pub fn try_write(&self) -> Result<WriteGuard<T>, ()> {
+        self.0.try_write().ok_or(())
+    }
+
     #[cfg(not(parallel_queries))]
     #[inline(always)]
     pub fn write(&self) -> WriteGuard<T> {