diff --git a/clang-tidy/readability/ImplicitBoolCastCheck.cpp b/clang-tidy/readability/ImplicitBoolCastCheck.cpp
index 764fd5d..49ddf7e 100644
--- a/clang-tidy/readability/ImplicitBoolCastCheck.cpp
+++ b/clang-tidy/readability/ImplicitBoolCastCheck.cpp
@@ -84,6 +84,7 @@ getZeroLiteralToCompareWithForGivenType(CastKind CastExpressionKind,
   default:
     assert(false && "Unexpected cast kind");
   }
+  return "";
 }
 
 bool isUnaryLogicalNotOperator(const Stmt *Statement) {