diff --git a/clang/include/clang/Analysis/FlowSensitive/Formula.h b/clang/include/clang/Analysis/FlowSensitive/Formula.h
index 0c7b1ecd02b17..64fe8f5b630a0 100644
--- a/clang/include/clang/Analysis/FlowSensitive/Formula.h
+++ b/clang/include/clang/Analysis/FlowSensitive/Formula.h
@@ -104,6 +104,7 @@ class alignas(const Formula *) Formula {
     case Equal:
       return 2;
     }
+    llvm_unreachable("Unhandled Formula::Kind enum");
   }
 
   Kind FormulaKind;