diff --git a/src/draw.cc b/src/draw.cc
index 674b0ac..721a95e 100644
--- a/src/draw.cc
+++ b/src/draw.cc
@@ -27,7 +27,7 @@ void bufferDrawLine(unsigned char* buf, int pitch, int x1, int y1, int x2, int y
 
         p1 = buf + pitch * y1 + x1;
         p2 = buf + pitch * y2 + x2;
-        while (p1 < p2) {
+        while (p1 <= p2) {
             *p1 = color;
             *p2 = color;
             p1 += pitch;