diff --git a/src/wasm/wat.ts b/src/wasm/wat.ts
index 4668726..551afad 100644
--- a/src/wasm/wat.ts
+++ b/src/wasm/wat.ts
@@ -215,7 +215,7 @@ function printBlockType(type: Blocktype, f: FmtCtx) {
 }
 
 function printMemarg(arg: MemArg, f: FmtCtx) {
-  if (arg.offset === undefined || arg.offset === 0) {
+  if (arg.offset !== undefined && arg.offset !== 0) {
     f.word(`offset=${arg.offset}`);
   }
   if (arg.align !== undefined) {
diff --git a/test.nil b/test.nil
index 1617fc6..f169233 100644
--- a/test.nil
+++ b/test.nil
@@ -66,4 +66,4 @@ function prInt(x: Int) = (
 function println(s: String) = (
   print(s);
   print("\n");
-);
\ No newline at end of file
+);