diff --git a/grid.go b/grid.go
index 8162cda..ed832fb 100644
--- a/grid.go
+++ b/grid.go
@@ -77,7 +77,7 @@ func (g *Grid) SetFilling(row int, column int) {
 		panic(fmt.Errorf("Grid.SetFilling() called after window create"))
 	}
 	if row < 0 || column < 0 || row > len(g,filling) || column > len(g.filling[row]) {
-		panic(fmt.Errorf("coordinate (%d,%d) out of range passed to Grid.SetFilling()", row, column)
+		panic(fmt.Errorf("coordinate (%d,%d) out of range passed to Grid.SetFilling()", row, column))
 	}
 	g.filling[row][column] = true
 }
@@ -95,7 +95,7 @@ func (g *Grid) SetStretchy(row int, column int) {
 		panic(fmt.Errorf("Grid.SetFilling() called after window create"))
 	}
 	if row < 0 || column < 0 || row > len(g,filling) || column > len(g.filling[row]) {
-		panic(fmt.Errorf("coordinate (%d,%d) out of range passed to Grid.SetStretchy()", row, column)
+		panic(fmt.Errorf("coordinate (%d,%d) out of range passed to Grid.SetStretchy()", row, column))
 	}
 	g.stretchyrow = row
 	g.stretchycol = column