Index: mlir/include/mlir/Dialect/Shape/IR/ShapeOps.td
===================================================================
--- mlir/include/mlir/Dialect/Shape/IR/ShapeOps.td
+++ mlir/include/mlir/Dialect/Shape/IR/ShapeOps.td
@@ -766,10 +766,13 @@
     concat([], [4,5,6]) -> [4,5,6]
   }];
 
-  let arguments = (ins Shape_ShapeType:$lhs, Shape_ShapeType:$rhs);
-  let results = (outs Shape_ShapeType:$result);
+  let arguments = (ins Shape_ShapeOrExtentTensorType:$lhs, Shape_ShapeOrExtentTensorType:$rhs);
+  let results = (outs Shape_ShapeOrExtentTensorType:$result);
+
+  let assemblyFormat = [{
+    $lhs `,` $rhs attr-dict `:` type($lhs) `,` type($rhs) `->` type($result)
+  }];
 
-  let assemblyFormat = "$lhs `,` $rhs attr-dict";
   let hasFolder = 1;
 }
 
Index: mlir/test/Dialect/Shape/canonicalize.mlir
===================================================================
--- mlir/test/Dialect/Shape/canonicalize.mlir
+++ mlir/test/Dialect/Shape/canonicalize.mlir
@@ -179,7 +179,7 @@
   // CHECK: shape.const_shape [0, 1, 2, 3] : !shape.shape
   %lhs = shape.const_shape [0, 1] : !shape.shape
   %rhs = shape.const_shape [2, 3] : !shape.shape
-  %0 = shape.concat %lhs, %rhs
+  %0 = shape.concat %lhs, %rhs : !shape.shape , !shape.shape -> !shape.shape
   return %0 : !shape.shape
 }
 
@@ -187,6 +187,18 @@
 
 // Basic case.
 // CHECK-LABEL: func @f
+func.func @f() -> tensor<4xindex> {
+  // CHECK: shape.const_shape [0, 1, 2, 3] : tensor<4xindex>
+  %lhs = shape.const_shape [0, 1] : tensor<2xindex>
+  %rhs = shape.const_shape [2, 3] : tensor<2xindex>
+  %0 = shape.concat %lhs, %rhs : tensor<2xindex>, tensor<2xindex> -> tensor<4xindex>
+  return %0 : tensor<4xindex>
+}
+
+// -----
+
+// Basic case.
+// CHECK-LABEL: func @f
 func.func @f() -> tensor<2xindex> {
   // CHECK: shape.const_shape [0, 1] : tensor<2xindex>
   %cs = shape.const_shape [0, 1] : !shape.shape