diff --git a/Utilities/IceT/src/ice-t/draw.c b/Utilities/IceT/src/ice-t/draw.c
index 1305e60..4deac22 100644
--- a/Utilities/IceT/src/ice-t/draw.c
+++ b/Utilities/IceT/src/ice-t/draw.c
@@ -313,10 +313,12 @@ static void find_contained_viewport(const GLdouble projection_matrix[16],
         }
     }
 
-    left = floor(left);
-    right = ceil(right);
-    bottom = floor(bottom);
-    top = ceil(top);
+  /* Round up or down with a little padding to make sure that we have not
+     clipped any due to numerical inaccuracies. */
+    left = floor(left) - 1;
+    right = ceil(right) + 1;
+    bottom = floor(bottom) - 1;
+    top = ceil(top) + 1;
 
   /* Clip bounds to global viewport. */
     if (left   < global_viewport[0]) left = global_viewport[0];