diff --git a/src/main/java/de/neemann/digital/gui/Main.java b/src/main/java/de/neemann/digital/gui/Main.java
index ad717b6b0..5ed8baef5 100644
--- a/src/main/java/de/neemann/digital/gui/Main.java
+++ b/src/main/java/de/neemann/digital/gui/Main.java
@@ -84,6 +84,7 @@ import java.util.List;
 import java.util.concurrent.ScheduledThreadPoolExecutor;
 
 import static de.neemann.digital.draw.shapes.GenericShape.SIZE;
+import static de.neemann.gui.ToolTipAction.getCTRLMask;
 import static javax.swing.JOptionPane.showInputDialog;
 
 /**
@@ -352,21 +353,16 @@ public final class Main extends JFrame implements ClosingWindowListener.ConfirmS
             public void actionPerformed(ActionEvent e) {
                 circuitComponent.scaleCircuit(1 / 0.9);
             }
-        }.setAcceleratorCTRLplus("PLUS");
-        // enable [+] which is SHIFT+[=] on english keyboard layout
-        circuitComponent.getInputMap().put(KeyStroke.getKeyStroke(KeyEvent.VK_EQUALS, KeyEvent.CTRL_DOWN_MASK, false), zoomIn);
-        circuitComponent.getInputMap().put(KeyStroke.getKeyStroke(KeyEvent.VK_ADD, KeyEvent.CTRL_DOWN_MASK, false), zoomIn);
-        circuitComponent.getActionMap().put(zoomIn, zoomIn);
+        }.setAcceleratorCTRLplus("PLUS").enableAcceleratorIn(circuitComponent);
+        circuitComponent.getInputMap().put(KeyStroke.getKeyStroke(KeyEvent.VK_ADD, getCTRLMask()), zoomIn);
 
         ToolTipAction zoomOut = new ToolTipAction(Lang.get("menu_zoomOut"), ICON_ZOOM_OUT) {
             @Override
             public void actionPerformed(ActionEvent e) {
                 circuitComponent.scaleCircuit(0.9);
             }
-        }.setAcceleratorCTRLplus("MINUS");
-        // enable [+] which is SHIFT+[=] on english keyboard layout
-        circuitComponent.getInputMap().put(KeyStroke.getKeyStroke(KeyEvent.VK_SUBTRACT, KeyEvent.CTRL_DOWN_MASK, false), zoomOut);
-        circuitComponent.getActionMap().put(zoomOut, zoomOut);
+        }.setAcceleratorCTRLplus("MINUS").enableAcceleratorIn(circuitComponent);
+        circuitComponent.getInputMap().put(KeyStroke.getKeyStroke(KeyEvent.VK_SUBTRACT, getCTRLMask()), zoomOut);
 
         ToolTipAction viewHelp = new ToolTipAction(Lang.get("menu_viewHelp"), ICON_HELP) {
             @Override
diff --git a/src/main/java/de/neemann/digital/gui/components/CircuitComponent.java b/src/main/java/de/neemann/digital/gui/components/CircuitComponent.java
index afb1a9aeb..fd7798a02 100644
--- a/src/main/java/de/neemann/digital/gui/components/CircuitComponent.java
+++ b/src/main/java/de/neemann/digital/gui/components/CircuitComponent.java
@@ -317,12 +317,10 @@ public class CircuitComponent extends JComponent implements ChangedListener, Lib
         }.setAcceleratorCTRLplus('D').enableAcceleratorIn(this);
 
         ToolTipAction plus = new PlusMinusAction(1).setAccelerator("PLUS").enableAcceleratorIn(this);
-        // enable [+] which is SHIFT+[=] on english keyboard layout
-        getInputMap().put(KeyStroke.getKeyStroke(KeyEvent.VK_EQUALS, 0, false), plus);
-        getInputMap().put(KeyStroke.getKeyStroke(KeyEvent.VK_ADD, 0, false), plus);
+        getInputMap().put(KeyStroke.getKeyStroke(KeyEvent.VK_ADD, 0), plus);
 
         ToolTipAction minus = new PlusMinusAction(-1).setAccelerator("MINUS").enableAcceleratorIn(this);
-        getInputMap().put(KeyStroke.getKeyStroke(KeyEvent.VK_SUBTRACT, 0, false), minus);
+        getInputMap().put(KeyStroke.getKeyStroke(KeyEvent.VK_SUBTRACT, 0), minus);
 
         new ToolTipAction(Lang.get("menu_programDiode")) {
             @Override
diff --git a/src/main/java/de/neemann/gui/ToolTipAction.java b/src/main/java/de/neemann/gui/ToolTipAction.java
index d6d6b7d3d..847cc186a 100644
--- a/src/main/java/de/neemann/gui/ToolTipAction.java
+++ b/src/main/java/de/neemann/gui/ToolTipAction.java
@@ -5,6 +5,8 @@
  */
 package de.neemann.gui;
 
+import de.neemann.digital.lang.Lang;
+
 import javax.swing.*;
 import java.awt.*;
 import java.awt.event.InputEvent;
@@ -85,7 +87,7 @@ public abstract class ToolTipAction extends AbstractAction {
      * @return this for call chaining
      */
     public ToolTipAction setAcceleratorCTRLplus(char key) {
-        return setAccelerator(KeyStroke.getKeyStroke(key, getAccMask()));
+        return setAccelerator(KeyStroke.getKeyStroke(key, getCTRLMask()));
     }
 
     /**
@@ -96,10 +98,13 @@ public abstract class ToolTipAction extends AbstractAction {
      */
     public ToolTipAction setAcceleratorCTRLplus(String key) {
         int keyCode = KeyStroke.getKeyStroke(key).getKeyCode();
-        return setAccelerator(KeyStroke.getKeyStroke(keyCode, getAccMask()));
+        return setAccelerator(KeyStroke.getKeyStroke(keyCode, getCTRLMask()));
     }
 
-    private int getAccMask() {
+    /**
+     * @return the system specific CTRL mask.
+     */
+    public static int getCTRLMask() {
         int mask = InputEvent.CTRL_DOWN_MASK;
         if (Screen.isMac())
             mask = InputEvent.META_DOWN_MASK;
@@ -123,6 +128,8 @@ public abstract class ToolTipAction extends AbstractAction {
      * @return this for call chaining
      */
     public ToolTipAction setAccelerator(KeyStroke accelerator) {
+        if (accelerator.getKeyCode() == KeyEvent.VK_PLUS && Lang.currentLanguage().getName().equals("en"))
+            accelerator = KeyStroke.getKeyStroke(KeyEvent.VK_EQUALS, accelerator.getModifiers());
         this.accelerator = accelerator;
         return this;
     }