diff --git a/mlir/include/mlir/Dialect/Tosa/IR/TosaProfileCompliance.h b/mlir/include/mlir/Dialect/Tosa/IR/TosaProfileCompliance.h
index 064264e73c8af..969d06afc70d6 100644
--- a/mlir/include/mlir/Dialect/Tosa/IR/TosaProfileCompliance.h
+++ b/mlir/include/mlir/Dialect/Tosa/IR/TosaProfileCompliance.h
@@ -148,6 +148,7 @@ class TosaProfileCompliance {
     case Extension::none:
       return {};
     };
+    llvm_unreachable("bad Extension type");
   }
 
   // Debug utilites.