diff --git a/build/context.mjs b/build/context.mjs
index 433a16c..bb2a8a8 100644
--- a/build/context.mjs
+++ b/build/context.mjs
@@ -12,7 +12,7 @@ const context = await esbuild.context({
     outdir: './dist/',
     platform: 'node',
     target: 'node10.4',
-    sourcemap: isDev ? 'external' : null,
+    sourcemap: isDev ? 'external' : false,
     loader: {
         '.node': 'copy',
     }