diff --git a/compiler/src/iree/compiler/Dialect/VM/Conversion/VMToEmitC/ConvertVMToEmitC.cpp b/compiler/src/iree/compiler/Dialect/VM/Conversion/VMToEmitC/ConvertVMToEmitC.cpp
index 7191ab541fac..f8d4ba03c97e 100644
--- a/compiler/src/iree/compiler/Dialect/VM/Conversion/VMToEmitC/ConvertVMToEmitC.cpp
+++ b/compiler/src/iree/compiler/Dialect/VM/Conversion/VMToEmitC/ConvertVMToEmitC.cpp
@@ -3215,7 +3215,7 @@ class FailOpConversion : public OpConversionPattern<IREE::VM::FailOp> {
 
       auto messageSizeIntOp = rewriter.create<emitc::CastOp>(
           /*location=*/loc,
-          /*type=*/rewriter.getIntegerType(32),
+          /*type=*/emitc::OpaqueType::get(ctx, "int"),
           /*operand=*/messageSizeOp);
 
       auto messageDataOp = emitc_builders::structMember(
diff --git a/compiler/src/iree/compiler/Dialect/VM/Conversion/VMToEmitC/test/control_flow_ops.mlir b/compiler/src/iree/compiler/Dialect/VM/Conversion/VMToEmitC/test/control_flow_ops.mlir
index a7c8e8a1dc27..501ef5e60143 100644
--- a/compiler/src/iree/compiler/Dialect/VM/Conversion/VMToEmitC/test/control_flow_ops.mlir
+++ b/compiler/src/iree/compiler/Dialect/VM/Conversion/VMToEmitC/test/control_flow_ops.mlir
@@ -298,12 +298,12 @@ vm.module @my_module {
     // CHECK-SAME:     : () -> !emitc.opaque<"iree_string_view_t">
     // CHECK-NEXT: %[[MSGSIZE:.+]] = emitc.call "EMITC_STRUCT_MEMBER"(%[[MSG]]) {args = [0 : index, #emitc.opaque<"size">]}
     // CHECK-SAME:     : (!emitc.opaque<"iree_string_view_t">) -> !emitc.opaque<"iree_host_size_t">
-    // CHECK-NEXT: %[[MSGSIZEINT:.+]] = emitc.cast %[[MSGSIZE]] : !emitc.opaque<"iree_host_size_t"> to i32
+    // CHECK-NEXT: %[[MSGSIZEINT:.+]] = emitc.cast %[[MSGSIZE]] : !emitc.opaque<"iree_host_size_t"> to !emitc.opaque<"int">
     // CHECK-NEXT: %[[MSGDATA:.+]] = emitc.call "EMITC_STRUCT_MEMBER"(%[[MSG]]) {args = [0 : index, #emitc.opaque<"data">]}
     // CHECK-SAME:     : (!emitc.opaque<"iree_string_view_t">) -> !emitc.ptr<!emitc.opaque<"const char">>
     // CHECK-NEXT: %[[FAILSTATUS:.+]] = emitc.call "iree_status_allocate_f"(%[[MSGSIZEINT]], %[[MSGDATA]])
     // CHECK-SAME:     {args = [#emitc.opaque<"IREE_STATUS_FAILED_PRECONDITION">, #emitc.opaque<"\22<vm>\22">, 0 : i32, #emitc.opaque<"\22%.*s\22">, 0 : index, 1 : index]}
-    // CHECK-SAME:     : (i32, !emitc.ptr<!emitc.opaque<"const char">>) -> !emitc.opaque<"iree_status_t">
+    // CHECK-SAME:     : (!emitc.opaque<"int">, !emitc.ptr<!emitc.opaque<"const char">>) -> !emitc.opaque<"iree_status_t">
     // CHECK-NEXT: return %[[FAILSTATUS]] : !emitc.opaque<"iree_status_t">
     vm.fail %arg0, "message"
   }