diff --git a/docs/Contributors.txt b/docs/Contributors.txt
index cc168fcac5..051611d885 100644
--- a/docs/Contributors.txt
+++ b/docs/Contributors.txt
@@ -1,4 +1,4 @@
-The following people contributed to Lazarus:
+The following people contributed to Lazarus:
 
 A. J. Venter
 Aleksey Lagunov
@@ -93,6 +93,7 @@ Sergio Marcelo
 Shane Miller
 Stefan Hille
 Taras Boychuk
+Tobias Giesen
 Tomas Gregorovic
 Tom Lisjac
 Tony Maro
diff --git a/lcl/interfaces/carbon/carbonproc.pp b/lcl/interfaces/carbon/carbonproc.pp
index ee7303ef28..426d803e93 100644
--- a/lcl/interfaces/carbon/carbonproc.pp
+++ b/lcl/interfaces/carbon/carbonproc.pp
@@ -712,10 +712,20 @@ end;
  ------------------------------------------------------------------------------}
 function CGRectToRect(const ARect: CGRect): TRect;
 begin
-  Result.Left := Floor(ARect.origin.x);
-  Result.Top := Floor(ARect.origin.y);
-  Result.Right := Ceil(ARect.origin.x + ARect.size.width);
-  Result.Bottom := Ceil(ARect.origin.y + ARect.size.height);
+  if CGRectIsNull(ARect) <> 0 then
+  begin // CGRect passed is invalid!
+    Result.Left := 0;
+    Result.Top := 0;
+    Result.Right := 0;
+    Result.Bottom := 0;
+  end
+  else
+  begin
+    Result.Left := Floor(ARect.origin.x);
+    Result.Top := Floor(ARect.origin.y);
+    Result.Right := Ceil(ARect.origin.x + ARect.size.width);
+    Result.Bottom := Ceil(ARect.origin.y + ARect.size.height);
+  end;
 end;
 
 {------------------------------------------------------------------------------
@@ -751,10 +761,20 @@ end;
  ------------------------------------------------------------------------------}
 function HIRectToCarbonRect(const ARect: HIRect): FPCMacOSAll.Rect;
 begin
-  Result.Left := Floor(ARect.origin.x);
-  Result.Top := Floor(ARect.origin.y);
-  Result.Right := Ceil(ARect.origin.x + ARect.size.width);
-  Result.Bottom := Ceil(ARect.origin.y + ARect.size.height);
+  if CGRectIsNull(ARect) <> 0 then
+  begin // CGRect passed is invalid!
+    Result.Left := 0;
+    Result.Top := 0;
+    Result.Right := 0;
+    Result.Bottom := 0;
+  end
+  else
+  begin
+    Result.Left := Floor(ARect.origin.x);
+    Result.Top := Floor(ARect.origin.y);
+    Result.Right := Ceil(ARect.origin.x + ARect.size.width);
+    Result.Bottom := Ceil(ARect.origin.y + ARect.size.height);
+  end;
 end;
 
 {------------------------------------------------------------------------------