diff --git a/SketchWidget.py b/SketchWidget.py
index fe3e74b..741c26e 100644
--- a/SketchWidget.py
+++ b/SketchWidget.py
@@ -28,6 +28,7 @@ class SketchWidget:
         self.axis_color = (1.0, 0.0, 0.0, 1.0)
         self.constraint_color = (0.8, 1.0, 0.0, 1.0)
         self.snap_angle = 10
+        self.snap_dist = 10
 
         try:
             # try double-buffered
@@ -254,10 +255,15 @@ class SketchWidget:
             start = self.drawingLine.getPt(0)
             angle = math.atan2(this_pt[1] - start[1], this_pt[0] - start[0])
             angle *= 180.0 / math.pi
-            def snaps_to(q): return abs(angle - q) < self.snap_angle
-            if snaps_to(-180) or snaps_to(180) or snaps_to(0):
+            def within(a, b, d): return abs(a - b) < d
+            def snaps_to(q): return within(angle, q, self.snap_angle)
+            if (snaps_to(-180) or snaps_to(180) or snaps_to(0)) \
+                    and within(start[1], this_pt[1],
+                            self.screenDistToDist(self.snap_dist)):
                 this_pt = (this_pt[0], start[1])
-            elif snaps_to(-90) or snaps_to(90):
+            elif (snaps_to(-90) or snaps_to(90)) \
+                    and within(start[0], this_pt[0],
+                            self.screenDistToDist(self.snap_dist)):
                 this_pt = (start[0], this_pt[1])
             self.drawingLine.setPt(1, this_pt)
             self.queue_redraw()