diff --git a/assembler/src/main.c b/assembler/src/main.c
index d2c57013..b5f06dc2 100644
--- a/assembler/src/main.c
+++ b/assembler/src/main.c
@@ -275,11 +275,11 @@ int main(int argc, char **argv)
 
 	err = yyparse();
 
-	yylex_destroy();
-
-	if (yyin)
+	if (strcmp(argv[0], "-"))
 		fclose(yyin);
 
+	yylex_destroy();
+
 	if (err || errors)
 		exit (1);