diff --git a/build/make/ads2gas.pl b/build/make/ads2gas.pl
index 533c85ba525ddc48c5740811140c1f21eb694734..69522bfd86e8911f24f40fb5a62f59f00c73d79c 100755
--- a/build/make/ads2gas.pl
+++ b/build/make/ads2gas.pl
@@ -21,7 +21,7 @@
 my $thumb = 0;
 
 foreach my $arg (@ARGV) {
-    $thumb = 1 if ($arg == "-thumb");
+    $thumb = 1 if ($arg eq "-thumb");
 }
 
 print "@ This file was created from a .asm file\n";