diff --git a/bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/ui/workbench/renderers/swt/CTabRendering.java b/bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/ui/workbench/renderers/swt/CTabRendering.java
index 2bc0d8f3eaf..d883ec57b96 100644
--- a/bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/ui/workbench/renderers/swt/CTabRendering.java
+++ b/bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/ui/workbench/renderers/swt/CTabRendering.java
@@ -400,8 +400,12 @@ private int[] computeSquareTabOutline(boolean onBottom, int startX, int endX, in
 						|| Objects.equals(outerKeylineColor, parent.getBackground())
 						? 0
 						: 1);
-		points[index++] = margin;
-		points[index++] = bottomY;
+
+		if (active) {
+			points[index++] = margin;
+			points[index++] = bottomY;
+		}
+
 		points[index++] = startX;
 		points[index++] = bottomY;
 
@@ -419,15 +423,6 @@ private int[] computeSquareTabOutline(boolean onBottom, int startX, int endX, in
 			points[index++] = bottomY;
 		}
 
-		points[index++] = parentSize.x - 1 - margin;
-		points[index++] = parentSize.y - 1;
-
-		points[index++] = points[0];
-		points[index++] = parentSize.y - 1;
-
-		points[index++] = points[0];
-		points[index++] = points[1];
-
 		int[] tmpPoints = new int[index];
 		System.arraycopy(points, 0, tmpPoints, 0, index);