diff --git a/org.fortiss.tooling.base.ui/src/org/fortiss/tooling/base/ui/editor/.ratings b/org.fortiss.tooling.base.ui/src/org/fortiss/tooling/base/ui/editor/.ratings
index ac8c5138b46b3f9e43e776e8e305e03f55ec3f0b..d12fd5381fd0dc307f1640c8308146aceb9e0dfb 100644
--- a/org.fortiss.tooling.base.ui/src/org/fortiss/tooling/base/ui/editor/.ratings
+++ b/org.fortiss.tooling.base.ui/src/org/fortiss/tooling/base/ui/editor/.ratings
@@ -1,6 +1,6 @@
 AdvancedTreeViewerEditorBase.java 9d9eded6848ee78991d1416592d1136efd71d2b7 GREEN
 AllocationDiagramEditorBase.java fa544546f73eea1150d90b7257b0e6bce82c288c GREEN
-CommonDiagramEditorBase.java 69994faea09eec342b8dfaa484ffc03b60978496 GREEN
+CommonDiagramEditorBase.java 67496a1bb97ba03c40d19409e02866fe8df1adf1 YELLOW
 ConstraintBasedProcessEditor.java 155a5a7ac41c668ae7ef978e8be13b83f5abd67d GREEN
 ConstraintBasedProcessEditorHelper.java 11d48e8a2aecd48eea259a42ef1192c4b292a334 GREEN
 DiagramEditorBase.java 09663ce095074d1a8eef086284eea0a7776e0431 GREEN
@@ -11,3 +11,4 @@ SourceEditorBase.java 662b921019fed964cd47838e8758194b66fa3a63 GREEN
 SourceEditorConfigurationBase.java e8b810c0d974c475f0a8e6f21aa5b6fd9e17c33a GREEN
 SourceEditorUndoRedo.java 08127a8e0afb4f9c2f4c21294ca3220282c25bf0 GREEN
 TreeViewerEditorBase.java 1c59689ff57c4f3cc180d85f13021fc03461ecb0 GREEN
+ZoomComboContributionItemFixed.java 274593bfb24461c39e70e048de6242e8a1660265 YELLOW
diff --git a/org.fortiss.tooling.base.ui/src/org/fortiss/tooling/base/ui/editor/CommonDiagramEditorBase.java b/org.fortiss.tooling.base.ui/src/org/fortiss/tooling/base/ui/editor/CommonDiagramEditorBase.java
index 69994faea09eec342b8dfaa484ffc03b60978496..67496a1bb97ba03c40d19409e02866fe8df1adf1 100644
--- a/org.fortiss.tooling.base.ui/src/org/fortiss/tooling/base/ui/editor/CommonDiagramEditorBase.java
+++ b/org.fortiss.tooling.base.ui/src/org/fortiss/tooling/base/ui/editor/CommonDiagramEditorBase.java
@@ -410,7 +410,7 @@ abstract class CommonDiagramEditorBase<T extends EObject> extends GEFEditorBase<
 			zoomManager.setZoomLevelContributions(getZoomLevelContributions());
 			registerZoomAction();
 		}
-		zoomContribution = new ZoomComboContributionItem(getSite().getPage());
+		zoomContribution = new ZoomComboContributionItemFixed(getSite().getPage());
 	}
 
 	/** Registers and returns the id of the given action. */
diff --git a/org.fortiss.tooling.base.ui/src/org/fortiss/tooling/base/ui/editor/ZoomComboContributionItemFixed.java b/org.fortiss.tooling.base.ui/src/org/fortiss/tooling/base/ui/editor/ZoomComboContributionItemFixed.java
new file mode 100644
index 0000000000000000000000000000000000000000..274593bfb24461c39e70e048de6242e8a1660265
--- /dev/null
+++ b/org.fortiss.tooling.base.ui/src/org/fortiss/tooling/base/ui/editor/ZoomComboContributionItemFixed.java
@@ -0,0 +1,53 @@
+/*-------------------------------------------------------------------------+
+| Copyright 2019 fortiss GmbH                                              |
+|                                                                          |
+| Licensed under the Apache License, Version 2.0 (the "License");          |
+| you may not use this file except in compliance with the License.         |
+| You may obtain a copy of the License at                                  |
+|                                                                          |
+|    http://www.apache.org/licenses/LICENSE-2.0                            |
+|                                                                          |
+| Unless required by applicable law or agreed to in writing, software      |
+| distributed under the License is distributed on an "AS IS" BASIS,        |
+| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
+| See the License for the specific language governing permissions and      |
+| limitations under the License.                                           |
++--------------------------------------------------------------------------*/
+package org.fortiss.tooling.base.ui.editor;
+
+import org.eclipse.gef.ui.actions.ZoomComboContributionItem;
+import org.eclipse.swt.SWT;
+import org.eclipse.swt.widgets.Composite;
+import org.eclipse.swt.widgets.Control;
+import org.eclipse.ui.IPartService;
+
+/**
+ * Overwrites {@link ZoomComboContributionItem} to fix the height adjustment of the zoom combo box.
+ * 
+ * @author diewald
+ */
+public class ZoomComboContributionItemFixed extends ZoomComboContributionItem {
+
+	/** See {@link ZoomComboContributionItem#ZoomComboContributionItem(IPartService)}. */
+	public ZoomComboContributionItemFixed(IPartService partService) {
+		super(partService);
+	}
+
+	/** See {@link ZoomComboContributionItem#ZoomComboContributionItem(IPartService, String)}. */
+	public ZoomComboContributionItemFixed(IPartService partService, String initString) {
+		super(partService, initString);
+	}
+
+	/** See {@link ZoomComboContributionItem#ZoomComboContributionItem(IPartService, String[])}. */
+	public ZoomComboContributionItemFixed(IPartService partService, String[] initStrings) {
+		super(partService, initStrings);
+	}
+
+	/** {@inheritDoc} */
+	@Override
+	protected Control createControl(Composite parent) {
+		Control control = super.createControl(parent);
+		parent.setSize(control.computeSize(SWT.DEFAULT, SWT.DEFAULT));
+		return control;
+	}
+}