diff --git a/vlib/v/gen/str.v b/vlib/v/gen/str.v
index 9890d7bdaa..50df270911 100644
--- a/vlib/v/gen/str.v
+++ b/vlib/v/gen/str.v
@@ -25,6 +25,7 @@ void _STR_PRINT_ARG(const char *fmt, char** refbufp, int *nbytes, int *memsize,
 		*memsize += (*memsize + *memsize) / 3 + guess;
 		*refbufp = (char*)realloc((void*)*refbufp, *memsize);
 	}
+	va_end(args);
 }
 
 string _STR(const char *fmt, int nfmts, ...) {