diff --git a/mlir/include/mlir/Dialect/StandardOps/Ops.td b/mlir/include/mlir/Dialect/StandardOps/Ops.td
--- a/mlir/include/mlir/Dialect/StandardOps/Ops.td
+++ b/mlir/include/mlir/Dialect/StandardOps/Ops.td
@@ -758,7 +758,7 @@
     static bool areCastCompatible(Type a, Type b);
   }];
 
-  let hasFolder = 0;
+  let hasFolder = 1;
 }
 
 def FPExtOp : CastOp<"fpext">, Arguments<(ins AnyType:$in)> {
diff --git a/mlir/lib/Dialect/StandardOps/Ops.cpp b/mlir/lib/Dialect/StandardOps/Ops.cpp
--- a/mlir/lib/Dialect/StandardOps/Ops.cpp
+++ b/mlir/lib/Dialect/StandardOps/Ops.cpp
@@ -1586,6 +1586,14 @@
          (a.isa<IntegerType>() && b.isIndex());
 }
 
+OpFoldResult IndexCastOp::fold(ArrayRef<Attribute> cstOperands) {
+  // Fold IndexCast(IndexCast(x)) -> x
+  auto cast = dyn_cast_or_null<IndexCastOp>(getOperand().getDefiningOp());
+  if (cast && cast.getOperand().getType() == getType())
+    return cast.getOperand();
+  return {};
+}
+
 //===----------------------------------------------------------------------===//
 // LoadOp
 //===----------------------------------------------------------------------===//
diff --git a/mlir/test/Transforms/canonicalize.mlir b/mlir/test/Transforms/canonicalize.mlir
--- a/mlir/test/Transforms/canonicalize.mlir
+++ b/mlir/test/Transforms/canonicalize.mlir
@@ -878,3 +878,12 @@
   // CHECK: return %[[C7]], %[[C11]]
   return %7, %8 : index, index
 }
+
+// CHECK-LABEL: func @index_cast
+// CHECK-SAME: %[[ARG_0:arg[0-9]+]]: i16
+func @index_cast(%arg0: i16) -> (i16) {
+  %11 = index_cast %arg0 : i16 to index
+  %12 = index_cast %11 : index to i16
+  // CHECK: return %[[ARG_0]] : i16
+  return %12 : i16
+}