diff --git a/pipi/paint/aline_template.h b/pipi/paint/aline_template.h
index fc267aa..c26aaba 100644
--- a/pipi/paint/aline_template.h
+++ b/pipi/paint/aline_template.h
@@ -97,7 +97,7 @@ else {
 		val2 = fractf(yend)*xgap;
 
     PLOT(ix1, iy1, val1);
-    PLOT(ix1, iy1+1, val2);
+    PLOT(ix1, (iy1+1)<y1?(iy1+1):iy1, val2);
 
 		xf = xend + g;
 
@@ -110,7 +110,7 @@ else {
 		val2 = fractf(yend)*xgap;
 
     PLOT(ix2, iy2,   val1);
-    PLOT(ix2, iy2+1, val2);
+    PLOT(ix2, (iy2+1)<y2?(iy2+1):iy2, val2);
 
 
 		for (y = (iy1+1); y < iy2; y++)
@@ -122,7 +122,7 @@ else {
         focus = (1.0 - fabsf(val1-val2));
         val1 += 0.3*focus;
         val2 += 0.3*focus;
-        PLOT(vx,   y, val1);
+        PLOT(vx, y, val1);
         vx++;
         PLOT(vx, y, val2);
         xf = xf + g;