diff --git a/bin/gsign b/bin/gsign
index 42ae8e6..a03c810 100755
--- a/bin/gsign
+++ b/bin/gsign
@@ -90,4 +90,4 @@ assert_path = File.join(release_path, "#{package_name}-build.assert")
 File.open(assert_path, "w") do |io|
   io.write result.to_yaml
 end
-system("#{program} -u \"#{signer}\" \"#{assert_path}\"")
+system!("#{program} -u \"#{signer}\" \"#{assert_path}\"")