diff --git a/mlir/test/Dialect/Affine/SuperVectorize/vectorize_unsupported.mlir b/mlir/test/Dialect/Affine/SuperVectorize/vectorize_unsupported.mlir
new file mode 100644
--- /dev/null
+++ b/mlir/test/Dialect/Affine/SuperVectorize/vectorize_unsupported.mlir
@@ -0,0 +1,11 @@
+// RUN: mlir-opt -allow-unregistered-dialect %s -affine-super-vectorizer-test  -vectorize-affine-loop-nest -split-input-file 2>&1 |  FileCheck %s
+
+func.func @unparallel_loop_reduction_unsupported(%in: memref<256x512xf32>, %out: memref<256xf32>) {
+ // CHECK: Outermost loop cannot be parallel
+ %cst = arith.constant 1.000000e+00 : f32
+ %final_red = affine.for %j = 0 to 512 iter_args(%red_iter = %cst) -> (f32) {
+   %add = arith.addf %red_iter, %red_iter : f32
+   affine.yield %add : f32
+ }
+ return
+}
diff --git a/mlir/test/lib/Dialect/Affine/TestVectorizationUtils.cpp b/mlir/test/lib/Dialect/Affine/TestVectorizationUtils.cpp
--- a/mlir/test/lib/Dialect/Affine/TestVectorizationUtils.cpp
+++ b/mlir/test/lib/Dialect/Affine/TestVectorizationUtils.cpp
@@ -92,7 +92,7 @@
   void testComposeMaps(llvm::raw_ostream &outs);
 
   /// Test for 'vectorizeAffineLoopNest' utility.
-  void testVecAffineLoopNest();
+  void testVecAffineLoopNest(llvm::raw_ostream &outs);
 };
 
 } // namespace
@@ -226,7 +226,7 @@
 }
 
 /// Test for 'vectorizeAffineLoopNest' utility.
-void VectorizerTestPass::testVecAffineLoopNest() {
+void VectorizerTestPass::testVecAffineLoopNest(llvm::raw_ostream &outs) {
   std::vector<SmallVector<AffineForOp, 2>> loops;
   gatherLoops(getOperation(), loops);
 
@@ -239,6 +239,13 @@
   VectorizationStrategy strategy;
   strategy.vectorSizes.push_back(4 /*vectorization factor*/);
   strategy.loopToVectorDim[outermostLoop] = 0;
+
+  ReductionLoopMap reductionLoops;
+  SmallVector<LoopReduction, 2> reductions;
+  if (!isLoopParallel(outermostLoop, &reductions)) {
+    outs << "Outermost loop cannot be parallel\n";
+    return;
+  }
   std::vector<SmallVector<AffineForOp, 2>> loopsToVectorize;
   loopsToVectorize.push_back({outermostLoop});
   (void)vectorizeAffineLoopNest(loopsToVectorize, strategy);
@@ -273,7 +280,7 @@
   }
 
   if (clTestVecAffineLoopNest)
-    testVecAffineLoopNest();
+    testVecAffineLoopNest(outs);
 
   if (!outs.str().empty()) {
     emitRemark(UnknownLoc::get(&getContext()), outs.str());