diff --git a/flang/lib/Optimizer/Builder/IntrinsicCall.cpp b/flang/lib/Optimizer/Builder/IntrinsicCall.cpp
index 090236fe3e5c..d754a8122e64 100644
--- a/flang/lib/Optimizer/Builder/IntrinsicCall.cpp
+++ b/flang/lib/Optimizer/Builder/IntrinsicCall.cpp
@@ -8547,7 +8547,7 @@ void IntrinsicLibrary::genTokenize(llvm::ArrayRef<fir::ExtendedValue> args) {
   // TOKENS is CHARACTER.  For form 2, FIRST is INTEGER.
   mlir::Type thirdArgEleTy = fir::getElementTypeOf(args[2]);
   bool isForm1 = fir::isa_char(thirdArgEleTy);
-  bool isForm2 = fir::isa_integer(thirdArgEleTy);
+  [[maybe_unused]] bool isForm2 = fir::isa_integer(thirdArgEleTy);
   assert((isForm1 || isForm2) &&
          "TOKENIZE third argument must be CHARACTER or INTEGER");