diff --git a/mlir/lib/Dialect/Tensor/IR/TensorOps.cpp b/mlir/lib/Dialect/Tensor/IR/TensorOps.cpp
--- a/mlir/lib/Dialect/Tensor/IR/TensorOps.cpp
+++ b/mlir/lib/Dialect/Tensor/IR/TensorOps.cpp
@@ -1267,11 +1267,11 @@
       return failure();
     SmallVector<int64_t> newSrcShape(srcType.getShape().begin(),
                                      srcType.getShape().end());
-    for (int64_t i = 0; i < srcType.getRank(); ++i) {
-      if (Optional<int64_t> constInt =
-              getConstantIntValue(insertSliceOp.getMixedSizes()[i]))
-        newSrcShape[i] = *constInt;
-    }
+    // Offsets / sizes / strides can be a subprefix of the rank; take only the
+    // leading dimensions.
+    for (auto en : llvm::enumerate(insertSliceOp.getMixedSizes()))
+      if (Optional<int64_t> constInt = getConstantIntValue(en.value()))
+        newSrcShape[en.index()] = *constInt;
 
     RankedTensorType newSrcType =
         RankedTensorType::get(newSrcShape, srcType.getElementType());
diff --git a/mlir/test/Dialect/Tensor/canonicalize.mlir b/mlir/test/Dialect/Tensor/canonicalize.mlir
--- a/mlir/test/Dialect/Tensor/canonicalize.mlir
+++ b/mlir/test/Dialect/Tensor/canonicalize.mlir
@@ -536,6 +536,21 @@
 
 // -----
 
+// CHECK-LABEL: func @insert_tensor_cast_on_insert_slice_src_prefix(
+// CHECK-SAME:      %[[arg0:.*]]: tensor<?x5x?xf32>, %[[arg1:.*]]: tensor<?x?x?xf32>
+//      CHECK:    %[[cast:.*]] = tensor.cast %[[arg0]] : tensor<?x5x?xf32> to tensor<64x5x?xf32>
+//      CHECK:    %[[r:.*]] =  tensor.insert_slice %[[cast]] into %[[arg1]][0, 1] [64, 5] [1, 1] : tensor<64x5x?xf32> into tensor<?x?x?xf32>
+//      CHECK:    return %[[r]]
+func @insert_tensor_cast_on_insert_slice_src_prefix(
+    %arg0 : tensor<?x5x?xf32>,  %arg1 : tensor<?x?x?xf32>, %sz0: index, %sz2: index) -> tensor<?x?x?xf32> {
+  %c64 = arith.constant 64: index
+  %r = tensor.insert_slice %arg0 into %arg1[0, 1] [%c64, 5] [1, 1]
+    : tensor<?x5x?xf32> into tensor<?x?x?xf32>
+  return %r : tensor<?x?x?xf32>
+}
+
+// -----
+
 // CHECK-LABEL: func @fold_extract_insert
 //  CHECK-SAME: %{{.+}}: tensor<?x?x?xf32>, %[[SLICE:.+]]: tensor<4x?x8xf32>
 func @fold_extract_insert(%input : tensor<?x?x?xf32>, %slice: tensor<4x?x8xf32>, %i: index, %size: index) -> (tensor<4x?x8xf32>) {