diff --git a/src/main/java/de/neemann/digital/gui/Main.java b/src/main/java/de/neemann/digital/gui/Main.java
index a27db084f..75af97f50 100644
--- a/src/main/java/de/neemann/digital/gui/Main.java
+++ b/src/main/java/de/neemann/digital/gui/Main.java
@@ -413,7 +413,22 @@ public class Main extends JFrame implements ClosingWindowListener.ConfirmSave, E
                 do {
                     repeat = false;
                     if (fc.showSaveDialog(Main.this) == JFileChooser.APPROVE_OPTION) {
+
                         final File selectedFile = fc.getSelectedFile();
+
+                        if (selectedFile.exists()) {
+                            Object[] options = {Lang.get("btn_overwrite"), Lang.get("btn_newName")};
+                            int res = JOptionPane.showOptionDialog(Main.this,
+                                    Lang.get("msg_fileExists", selectedFile.getName()),
+                                    Lang.get("msg_warning"),
+                                    JOptionPane.DEFAULT_OPTION, JOptionPane.WARNING_MESSAGE,
+                                    null, options, options[0]);
+                            if (res == 1) {
+                                repeat = true;
+                                continue;
+                            }
+                        }
+
                         if (library.isFileAccessible(selectedFile))
                             saveFile(selectedFile, false);
                         else {
diff --git a/src/main/java/de/neemann/digital/gui/components/table/TableDialog.java b/src/main/java/de/neemann/digital/gui/components/table/TableDialog.java
index fc3570185..40afa3b12 100644
--- a/src/main/java/de/neemann/digital/gui/components/table/TableDialog.java
+++ b/src/main/java/de/neemann/digital/gui/components/table/TableDialog.java
@@ -260,15 +260,35 @@ public class TableDialog extends JDialog {
                 JFileChooser fc = new JFileChooser();
                 if (TableDialog.this.filename != null)
                     fc.setSelectedFile(Main.checkSuffix(TableDialog.this.filename, "tru"));
-                if (fc.showSaveDialog(TableDialog.this) == JFileChooser.APPROVE_OPTION) {
-                    try {
-                        File file = Main.checkSuffix(fc.getSelectedFile(), "tru");
-                        model.getTable().save(file);
-                        TableDialog.this.filename = file;
-                    } catch (IOException e1) {
-                        new ErrorMessage().addCause(e1).show(TableDialog.this);
+
+                boolean repeat;
+                do {
+                    repeat = false;
+                    if (fc.showSaveDialog(TableDialog.this) == JFileChooser.APPROVE_OPTION) {
+                        final File selectedFile = fc.getSelectedFile();
+
+                        if (selectedFile.exists()) {
+                            Object[] options = {Lang.get("btn_overwrite"), Lang.get("btn_newName")};
+                            int res = JOptionPane.showOptionDialog(TableDialog.this,
+                                    Lang.get("msg_fileExists", selectedFile.getName()),
+                                    Lang.get("msg_warning"),
+                                    JOptionPane.DEFAULT_OPTION, JOptionPane.WARNING_MESSAGE,
+                                    null, options, options[0]);
+                            if (res == 1) {
+                                repeat = true;
+                                continue;
+                            }
+                        }
+
+                        try {
+                            File file = Main.checkSuffix(selectedFile, "tru");
+                            model.getTable().save(file);
+                            TableDialog.this.filename = file;
+                        } catch (IOException e1) {
+                            new ErrorMessage().addCause(e1).show(TableDialog.this);
+                        }
                     }
-                }
+                } while (repeat);
             }
         });
 
diff --git a/src/main/resources/lang/lang_de.xml b/src/main/resources/lang/lang_de.xml
index 060532901..b62d0b1e3 100644
--- a/src/main/resources/lang/lang_de.xml
+++ b/src/main/resources/lang/lang_de.xml
@@ -38,6 +38,7 @@
     <string name="btn_addTransitions_tt">Alle möglichen Übergänge werden als Testfälle ergänzt. Dient zur Erzeugung von Testfällen für den Simulator selbst.</string>
     <string name="btn_newName">Neuer Name</string>
     <string name="btn_saveAnyway">Trotzdem speichern</string>
+    <string name="btn_overwrite">Überschreiben</string>
     <string name="msg_warning">Warnung</string>
     <string name="cancel">Abbrechen</string>
     <string name="digital">Digital</string>
@@ -739,6 +740,7 @@ Die Icons stammen aus dem Tango Desktop Project.</string>
     <string name="msg_fileNotAccessible">Dieser Dateiename ist nicht aus dem aktuellen Projekt importierbar!</string>
     <string name="msg_fileIsNotUnique">Der Dateiname ist nicht eindeutig!</string>
     <string name="msg_fileNotImportedYet">Die Datei wurde noch nicht importiert.</string>
+    <string name="msg_fileExists">Die Datei {0} existiert schon!</string>
 
     <string name="ok">Ok</string>
     <string name="rot_0">0°</string>
diff --git a/src/main/resources/lang/lang_en.xml b/src/main/resources/lang/lang_en.xml
index 76f9bc351..719642a22 100644
--- a/src/main/resources/lang/lang_en.xml
+++ b/src/main/resources/lang/lang_en.xml
@@ -38,6 +38,7 @@
     <string name="btn_addTransitions_tt">All possible transitions are added as test cases. Is used to create test cases to test the simulator itself.</string>
     <string name="btn_newName">New Name</string>
     <string name="btn_saveAnyway">Save anyway</string>
+    <string name="btn_overwrite">Overwrite</string>
     <string name="msg_warning">Warning</string>
     <string name="cancel">Cancel</string>
     <string name="digital">Digital</string>
@@ -726,6 +727,7 @@ The icons are taken from the Tango Desktop Project.</string>
     <string name="msg_fileNotAccessible">The selected file name is not importable from the actual project!</string>
     <string name="msg_fileIsNotUnique">The file name is not unique!</string>
     <string name="msg_fileNotImportedYet">The file has not yet been imported.</string>
+    <string name="msg_fileExists">The file {0} already exists!</string>
 
     <string name="ok">Ok</string>
     <string name="rot_0">0°</string>