diff --git a/graphics/nxglib/nxglib_nonintersecting.c b/graphics/nxglib/nxglib_nonintersecting.c
index b498e6294c..1aa06c0a26 100644
--- a/graphics/nxglib/nxglib_nonintersecting.c
+++ b/graphics/nxglib/nxglib_nonintersecting.c
@@ -95,21 +95,21 @@ void nxgl_nonintersecting(FAR struct nxgl_rect_s result[4],
   result[NX_TOP_NDX].pt1.x    = rect1->pt1.x;
   result[NX_TOP_NDX].pt1.y    = rect1->pt1.y;
   result[NX_TOP_NDX].pt2.x    = rect1->pt2.x;
-  result[NX_TOP_NDX].pt2.y    = intersection.pt1.y;
+  result[NX_TOP_NDX].pt2.y    = intersection.pt1.y - 1;
 
   result[NX_BOTTOM_NDX].pt1.x = rect1->pt1.x;
-  result[NX_BOTTOM_NDX].pt1.y = intersection.pt2.y;
+  result[NX_BOTTOM_NDX].pt1.y = intersection.pt2.y + 1;
   result[NX_BOTTOM_NDX].pt2.x = rect1->pt2.x;
   result[NX_BOTTOM_NDX].pt2.y = rect1->pt2.y;
 
-  result[NX_LEFT_NDX].pt1.x   = rect1->pt1.x;
+  result[NX_LEFT_NDX].pt1.x   = rect1->pt1.x + 1;
   result[NX_LEFT_NDX].pt1.y   = intersection.pt1.y;
   result[NX_LEFT_NDX].pt2.x   = intersection.pt1.x;
   result[NX_LEFT_NDX].pt2.y   = intersection.pt2.y;
 
   result[NX_RIGHT_NDX].pt1.x  = intersection.pt2.x;
   result[NX_RIGHT_NDX].pt1.y  = intersection.pt1.y;
-  result[NX_RIGHT_NDX].pt2.x  = rect1->pt2.x;
+  result[NX_RIGHT_NDX].pt2.x  = rect1->pt2.x - 1;
   result[NX_RIGHT_NDX].pt2.y  = intersection.pt2.y;
 }
 
diff --git a/graphics/nxglib/nxglib_rectoverlap.c b/graphics/nxglib/nxglib_rectoverlap.c
index ec33d8969c..4b741e7981 100644
--- a/graphics/nxglib/nxglib_rectoverlap.c
+++ b/graphics/nxglib/nxglib_rectoverlap.c
@@ -82,9 +82,9 @@ boolean nxgl_rectoverlap(FAR struct nxgl_rect_s *rect1,
    * the two rectangles overlap in some fashion.
    */
 
-  return (rect1->pt1.x < rect2->pt2.x) &&  /* FALSE: rect1 is wholly to the right */
-         (rect2->pt1.x < rect1->pt2.x) &&  /* FALSE: rect2 is wholly to the right */
-         (rect1->pt1.y < rect2->pt2.y) &&  /* FALSE: rect1 is wholly below rect2 */
-         (rect2->pt1.y < rect1->pt2.y);    /* FALSE: rect2 is wholly below rect1 */
+  return (rect1->pt1.x <= rect2->pt2.x) &&  /* FALSE: rect1 is wholly to the right */
+         (rect2->pt1.x <= rect1->pt2.x) &&  /* FALSE: rect2 is wholly to the right */
+         (rect1->pt1.y <= rect2->pt2.y) &&  /* FALSE: rect1 is wholly below rect2 */
+         (rect2->pt1.y <= rect1->pt2.y);    /* FALSE: rect2 is wholly below rect1 */
 }