diff --git a/action.js b/action.js
index 6ac835d..09df795 100644
--- a/action.js
+++ b/action.js
@@ -31,9 +31,12 @@ for (let modPy of readdirSync(".").filter((f) => f.slice(-3) == ".py")) {
   mkdirSync(`${libName}/${modName}`);
 
   // compile mpy file
-  execSync(`pipx run mpy-cross ${modPy} -o ${libName}/${modMpyPath}`, {
-    encoding: "utf8",
-  });
+  execSync(
+    `pipx run mpy-cross -march=armv6m ${modPy} -o ${libName}/${modMpyPath}`,
+    {
+      encoding: "utf8",
+    },
+  );
 
   // Add module files to repo
   writeFileSync(`${libName}/${modInitPath}`, "");