diff --git a/src/path/PathItem.Boolean.js b/src/path/PathItem.Boolean.js
index c78d6b9d..eba29940 100644
--- a/src/path/PathItem.Boolean.js
+++ b/src/path/PathItem.Boolean.js
@@ -748,13 +748,29 @@ PathItem.inject(new function() {
                     // While subtracting, we need to omit this curve if it is
                     // contributing to the second operand and is outside the
                     // first operand.
-                    var wind = !(operator.subtract && path2 && (
-                            operand === path1 &&
-                                path2._getWinding(pt, dir, true).winding ||
-                            operand === path2 &&
-                                !path1._getWinding(pt, dir, true).winding))
-                            ? getWinding(pt, curves, dir, true)
-                            : { winding: 0, quality: 1 };
+                    var wind = null;
+                    if (operator.subtract && path2) {
+                        // calculate path winding at point depending on operand
+                        var pathWinding = operand === path1
+                                          ? path2._getWinding(pt, dir, true)
+                                          : path1._getWinding(pt, dir, true);
+                        // if curve should be omitted
+                        if (operand === path1 && pathWinding.winding ||
+                            operand === path2 && !pathWinding.winding) {
+                            // if quality is not good enough
+                            if (pathWinding.quality < 1) {
+                                // skip this point
+                                continue;
+                            } else {
+                                // omit curve
+                                wind = {winding: 0, quality: 1};
+                            }
+                        }
+                    }
+                    // default case
+                    if (wind === null) {
+                        wind = getWinding(pt, curves, dir, true);
+                    }
                     if (wind.quality > winding.quality)
                         winding = wind;
                     break;
diff --git a/test/tests/Path_Boolean.js b/test/tests/Path_Boolean.js
index 083b212b..ed9061f8 100644
--- a/test/tests/Path_Boolean.js
+++ b/test/tests/Path_Boolean.js
@@ -1189,3 +1189,17 @@ test('Isolated edge-cases from @iconexperience\'s boolean-test suite', function(
         compareBoolean(path1.intersect(path2), result[1], 'path1.intersect(path2); // Test ' + (i + 1));
     }
 });
+
+test('#1506', function () {
+    var path1 = new Path('M250,175c27.61424,0 50,22.38576 50,50c0,27.61424 -22.38576,50 -50,50c-9.10718,0 -17.64567,-2.43486 -25,-6.68911c14.94503,-8.64524 25,-24.80383 25,-43.31089c0,-18.50706 -10.05497,-34.66565 -25,-43.31089c7.35433,-4.25425 15.89282,-6.68911 25,-6.68911z');
+    var path2 = new Path('M250,225c0,-27.61424 22.38576,-50 50,-50c27.61424,0 50,22.38576 50,50c0,27.61424 -22.38576,50 -50,50c-27.61424,0 -50,-22.38576 -50,-50z');
+    var result = 'M250,175c9.10718,0 17.64567,2.43486 25,6.68911c-14.94503,8.64523 -25,24.80383 -25,43.31089c0,18.50706 10.05497,34.66566 25,43.31089c-7.35433,4.25425 -15.89282,6.68911 -25,6.68911c-9.10718,0 -17.64567,-2.43486 -25,-6.68911c14.94503,-8.64524 25,-24.80383 25,-43.31089c0,-18.50706 -10.05497,-34.66565 -25,-43.31089c7.35433,-4.25425 15.89282,-6.68911 25,-6.68911z';
+    compareBoolean(path1.subtract(path2), result);
+});
+
+test('#1513', function () {
+    var path1  = PathItem.create('M100,200v-100h200v100z');
+    var path2  = PathItem.create('M200,100c55.22847,0 100,44.77153 100,100h-200c0,-55.22847 44.77153,-100 100,-100z');
+    var result = 'M100,100h200v100c0,-55.22847 -44.77153,-100 -100,-100c-55.22847,0 -100,44.77153 -100,100z';
+    compareBoolean(path1.subtract(path2), result);
+});
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