diff --git a/src/vertex-clipping.c b/src/vertex-clipping.c
index db527e14..2bb8c0ab 100644
--- a/src/vertex-clipping.c
+++ b/src/vertex-clipping.c
@@ -206,6 +206,9 @@ clip_polygon_left(struct clip_context *ctx, const struct polygon8 *src,
 	enum path_transition trans;
 	int i;
 
+	if (src->n < 2)
+		return 0;
+
 	clip_context_prepare(ctx, src, dst_x, dst_y);
 	for (i = 0; i < src->n; i++) {
 		trans = path_transition_left_edge(ctx, src->x[i], src->y[i]);
@@ -222,6 +225,9 @@ clip_polygon_right(struct clip_context *ctx, const struct polygon8 *src,
 	enum path_transition trans;
 	int i;
 
+	if (src->n < 2)
+		return 0;
+
 	clip_context_prepare(ctx, src, dst_x, dst_y);
 	for (i = 0; i < src->n; i++) {
 		trans = path_transition_right_edge(ctx, src->x[i], src->y[i]);
@@ -238,6 +244,9 @@ clip_polygon_top(struct clip_context *ctx, const struct polygon8 *src,
 	enum path_transition trans;
 	int i;
 
+	if (src->n < 2)
+		return 0;
+
 	clip_context_prepare(ctx, src, dst_x, dst_y);
 	for (i = 0; i < src->n; i++) {
 		trans = path_transition_top_edge(ctx, src->x[i], src->y[i]);
@@ -254,6 +263,9 @@ clip_polygon_bottom(struct clip_context *ctx, const struct polygon8 *src,
 	enum path_transition trans;
 	int i;
 
+	if (src->n < 2)
+		return 0;
+
 	clip_context_prepare(ctx, src, dst_x, dst_y);
 	for (i = 0; i < src->n; i++) {
 		trans = path_transition_bottom_edge(ctx, src->x[i], src->y[i]);