diff --git a/clang/test/Sema/warn-unused-but-set-variables.c b/clang/test/Sema/warn-unused-but-set-variables.c
--- a/clang/test/Sema/warn-unused-but-set-variables.c
+++ b/clang/test/Sema/warn-unused-but-set-variables.c
@@ -23,6 +23,10 @@
   int a;
   w = (a = 0);
 
+  // Following gcc, warn for a volatile variable.
+  volatile int b; // expected-warning{{variable 'b' set but not used}}
+  b = 0;
+
   int x;
   x = 0;
   return x;