diff --git a/mlir/include/mlir/IR/OpDefinition.h b/mlir/include/mlir/IR/OpDefinition.h
--- a/mlir/include/mlir/IR/OpDefinition.h
+++ b/mlir/include/mlir/IR/OpDefinition.h
@@ -21,6 +21,7 @@
 
 #include "mlir/IR/Operation.h"
 #include <type_traits>
+#include "llvm/Support/Debug.h"
 
 namespace mlir {
 class Builder;
@@ -979,8 +980,9 @@
 
   /// Return true if this "op class" can match against the specified operation.
   static bool classof(Operation *op) {
-    if (auto *abstractOp = op->getAbstractOperation())
-      return &classof == abstractOp->classof;
+    if (auto *abstractOp = op->getAbstractOperation()) {
+      if(&classof == abstractOp->classof) return true;
+    }
     return op->getName().getStringRef() == ConcreteType::getOperationName();
   }