diff --git a/clang/lib/Analysis/ThreadSafety.cpp b/clang/lib/Analysis/ThreadSafety.cpp
--- a/clang/lib/Analysis/ThreadSafety.cpp
+++ b/clang/lib/Analysis/ThreadSafety.cpp
@@ -1641,8 +1641,8 @@
     // Otherwise the negative requirement must be propagated to the caller.
     LDat = FSet.findLock(Analyzer->FactMan, Cp);
     if (!LDat) {
-      Analyzer->Handler.handleMutexNotHeld("", D, POK, Cp.toString(),
-                                           LK_Shared, Loc);
+      Analyzer->Handler.handleMutexNotHeld("negative capability", D, POK,
+                                           Cp.toString(), LK_Shared, Loc);
     }
     return;
   }
diff --git a/clang/test/SemaCXX/warn-thread-safety-analysis.cpp b/clang/test/SemaCXX/warn-thread-safety-analysis.cpp
--- a/clang/test/SemaCXX/warn-thread-safety-analysis.cpp
+++ b/clang/test/SemaCXX/warn-thread-safety-analysis.cpp
@@ -4985,7 +4985,7 @@
   }
 
   void bar() {
-    bar2();       // expected-warning {{calling function 'bar2' requires holding  '!mu'}}
+    bar2();       // expected-warning {{calling function 'bar2' requires holding negative capability '!mu'}}
   }
 
   void bar2() EXCLUSIVE_LOCKS_REQUIRED(!mu) {
diff --git a/clang/test/SemaCXX/warn-thread-safety-negative.cpp b/clang/test/SemaCXX/warn-thread-safety-negative.cpp
--- a/clang/test/SemaCXX/warn-thread-safety-negative.cpp
+++ b/clang/test/SemaCXX/warn-thread-safety-negative.cpp
@@ -50,7 +50,7 @@
   }
 
   void bar() {
-    baz();        // expected-warning {{calling function 'baz' requires holding  '!mu'}}
+    baz();        // expected-warning {{calling function 'baz' requires holding negative capability '!mu'}}
   }
 
   void baz() EXCLUSIVE_LOCKS_REQUIRED(!mu) {