diff --git a/README.md b/README.md
index ca7a50c..cff44ae 100644
--- a/README.md
+++ b/README.md
@@ -54,7 +54,7 @@ signAsync({
 `app` - *String*
 
 Path to the application package.
-Needs file extension `.app`.
+Needs file extension `.app`. NOTE: if your app name contains the space character, please rename the .app and the binary in `.app/Contents/MacOS/` without the space character; otherwise, it will throw an error.
 
 **Optional**
 
diff --git a/src/util.ts b/src/util.ts
index 9a7e5c4..a81afe4 100644
--- a/src/util.ts
+++ b/src/util.ts
@@ -107,6 +107,10 @@ export async function validateOptsApp (opts: BaseSignOptions): Promise<void> {
   if (!(await fs.pathExists(opts.app))) {
     throw new Error(`Application at path "${opts.app}" could not be found`);
   }
+  const pathWithSpaceEscapeChars = opts.app.replace(/(\s+)/g, '\\$1');
+  if (opts.app !== pathWithSpaceEscapeChars) {
+    throw new Error(`Application name "${opts.app}" with space is not supported.`);
+  }
 }
 
 /**