diff --git a/scripts/generate_features.pl b/scripts/generate_features.pl
index b99c637..f680951 100755
--- a/scripts/generate_features.pl
+++ b/scripts/generate_features.pl
@@ -66,11 +66,14 @@
             $in_section = 0;
             next;
         }
-
-        my ($define) = $line =~ /#define (\w+)/;
-        $feature_defines .= "#if defined(${define})\n";
+        # Strip leading MBEDTLS_ to save binary size
+        my ($mbedtls_prefix, $define) = $line =~ /#define (MBEDTLS_)?(\w+)/;
+        if (!$mbedtls_prefix) {
+            die "Feature does not start with 'MBEDTLS_': $line\n";
+        }
+        $feature_defines .= "#if defined(MBEDTLS_${define})\n";
         $feature_defines .= "    \"${define}\",\n";
-        $feature_defines .= "#endif /* ${define} */\n";
+        $feature_defines .= "#endif /* MBEDTLS_${define} */\n";
     }
 
     if (!$in_section) {