diff --git a/libass/ass_outline.c b/libass/ass_outline.c
index ae5c06a..2173508 100644
--- a/libass/ass_outline.c
+++ b/libass/ass_outline.c
@@ -613,7 +613,7 @@ static bool draw_arc(StrokerState *str, ASS_Vector pt,
                      ASS_DVector normal0, ASS_DVector normal1, double c, int dir)
 {
     enum { max_subdiv = 15 };
-    double mul[max_subdiv + 1];
+    double mul[16];
 
     ASS_DVector center;
     bool small_angle = true;
@@ -649,7 +649,7 @@ static bool draw_arc(StrokerState *str, ASS_Vector pt,
 static bool draw_circle(StrokerState *str, ASS_Vector pt, int dir)
 {
     enum { max_subdiv = 15 };
-    double mul[max_subdiv + 1], c = 0;
+    double mul[16], c = 0;
 
     int pos = max_subdiv;
     while (c < str->split_cos && pos) {