diff --git a/mlir/lib/Dialect/Vector/IR/VectorOps.cpp b/mlir/lib/Dialect/Vector/IR/VectorOps.cpp
--- a/mlir/lib/Dialect/Vector/IR/VectorOps.cpp
+++ b/mlir/lib/Dialect/Vector/IR/VectorOps.cpp
@@ -381,7 +381,8 @@
     if (auto dstVecType = dyn_cast<VectorType>(reductionOp.getDestType())) {
       if (mask) {
         VectorType newMaskType =
-            VectorType::get(dstVecType.getShape(), rewriter.getI1Type());
+            VectorType::get(dstVecType.getShape(), rewriter.getI1Type(),
+                            dstVecType.getScalableDims());
         mask = rewriter.create<vector::ShapeCastOp>(loc, newMaskType, mask);
       }
       cast = rewriter.create<vector::ShapeCastOp>(
diff --git a/mlir/test/Dialect/Vector/canonicalize.mlir b/mlir/test/Dialect/Vector/canonicalize.mlir
--- a/mlir/test/Dialect/Vector/canonicalize.mlir
+++ b/mlir/test/Dialect/Vector/canonicalize.mlir
@@ -8,7 +8,6 @@
   %0 = vector.create_mask %c3, %c2 : vector<4x3xi1>
   return %0 : vector<4x3xi1>
 }
-
 // -----
 
 // CHECK-LABEL: create_scalable_vector_mask_to_constant_mask
@@ -1320,6 +1319,24 @@
     return %0 : vector<5x4x20xf32>
 }
 
+// -----
+// CHECK-LABEL:   func.func @vector_multi_reduction_scalable(
+// CHECK-SAME:     %[[VAL_0:.*]]: vector<1x[4]x1xf32>,
+// CHECK-SAME:     %[[VAL_1:.*]]: vector<1x[4]xf32>,
+// CHECK-SAME:     %[[VAL_2:.*]]: vector<1x[4]x1xi1>)
+func.func @vector_multi_reduction_scalable(%source: vector<1x[4]x1xf32>,
+                                           %acc: vector<1x[4]xf32>,
+                                           %mask: vector<1x[4]x1xi1>) -> vector<1x[4]xf32> {
+// CHECK:           %[[VAL_3:.*]] = vector.shape_cast %[[VAL_2]] : vector<1x[4]x1xi1> to vector<1x[4]xi1>
+// CHECK:           %[[VAL_4:.*]] = vector.shape_cast %[[VAL_0]] : vector<1x[4]x1xf32> to vector<1x[4]xf32>
+// CHECK:           %[[VAL_5:.*]] = arith.addf %[[VAL_1]], %[[VAL_4]] : vector<1x[4]xf32>
+// CHECK:           %[[VAL_6:.*]] = arith.select %[[VAL_3]], %[[VAL_5]], %[[VAL_4]] : vector<1x[4]xi1>, vector<1x[4]xf32>
+    %0 = vector.mask %mask { vector.multi_reduction <add>, %source, %acc [2] : vector<1x[4]x1xf32> to vector<1x[4]xf32> } :
+          vector<1x[4]x1xi1> -> vector<1x[4]xf32>
+
+    return %0 : vector<1x[4]xf32>
+}
+
 // -----
 
 // CHECK-LABEL: func @masked_vector_multi_reduction_unit_dimensions