diff --git a/src/main/java/ch/repnik/intellij/CommitPrefixCheckinHandler.java b/src/main/java/ch/repnik/intellij/CommitPrefixCheckinHandler.java
index 84cb314..22ae908 100644
--- a/src/main/java/ch/repnik/intellij/CommitPrefixCheckinHandler.java
+++ b/src/main/java/ch/repnik/intellij/CommitPrefixCheckinHandler.java
@@ -13,10 +13,12 @@
 import com.intellij.openapi.vcs.ProjectLevelVcsManager;
 import com.intellij.openapi.vcs.checkin.CheckinHandler;
 import com.intellij.openapi.vcs.impl.ProjectLevelVcsManagerImpl;
+import com.intellij.openapi.vcs.ui.CommitMessage;
 import com.intellij.openapi.vcs.ui.RefreshableOnComponent;
 import com.intellij.psi.PsiDocumentManager;
 import com.intellij.psi.impl.PsiDocumentManagerImpl;
 import com.intellij.util.messages.MessageBusConnection;
+import com.intellij.util.ui.UIUtil;
 import git4idea.GitLocalBranch;
 import git4idea.branch.GitBranchUtil;
 import git4idea.repo.GitRepository;
@@ -53,7 +55,7 @@ private void updateCommitMessage() {
             PsiDocumentManager psiInstance = PsiDocumentManager.getInstance(this.panel.getProject());
               if (psiInstance instanceof PsiDocumentManagerImpl) {
                 if (!((PsiDocumentManagerImpl) psiInstance).isCommitInProgress()) {
-                  panel.setCommitMessage(getNewCommitMessage());
+                  getNewCommitMessage().ifPresent(this::setCommitMessageWithoutFocus);
                 } else {
                     log.info("PsiDocumentManager reported commit in progress. Skipping Git Auto Prefix");
                 }
@@ -63,6 +65,22 @@ private void updateCommitMessage() {
             });
   }
 
+  /**
+   * Sets the commit message without requesting focus.
+   * panel.setCommitMessage() would call CommitMessageUi.focus() (see CommitProjectPanelAdapter)
+   * which steals the focus e.g. from the terminal when switching branches.
+   */
+  private void setCommitMessageWithoutFocus(String newMessage) {
+    CommitMessage commitMessageComponent =
+        UIUtil.findComponentOfType(panel.getComponent(), CommitMessage.class);
+    if (commitMessageComponent != null) {
+      commitMessageComponent.setCommitMessage(newMessage);
+    } else {
+      // Fallback for unknown CheckinProjectPanel implementations (may move focus)
+      panel.setCommitMessage(newMessage);
+    }
+  }
+
   @Nullable
   @Override
   public RefreshableOnComponent getBeforeCheckinConfigurationPanel() {
@@ -71,18 +89,30 @@ public RefreshableOnComponent getBeforeCheckinConfigurationPanel() {
     return super.getBeforeCheckinConfigurationPanel();
   }
 
-  private String getNewCommitMessage() {
+  private Optional<String> getNewCommitMessage() {
     String branchName = extractBranchName();
     // log.warn("BranchName: " + branchName);
 
-    Optional<String> ticketName = getTicket(getTicketSystem(), branchName);
+    return calculateNewCommitMessage(getTicketSystem(), branchName, panel.getCommitMessage(),
+        getWrapLeft(), getWrapRight(), getIssueKeyPosition());
+  }
+
+  static Optional<String> calculateNewCommitMessage(TicketSystem ticketSystem, String branchName,
+      String currentMessage, String wrapLeft, String wrapRight, Position issueKeyPosition) {
+    Optional<String> ticketName = getTicket(ticketSystem, branchName);
 
-    if (ticketName.isPresent()) {
-      // Sets the value for the new Panel UI
-      return updatePrefix(ticketName.get(), panel.getCommitMessage(), getTicketSystem(), getWrapLeft(), getWrapRight(), getIssueKeyPosition());
+    if (!ticketName.isPresent()) {
+      return Optional.empty();
+    }
+
+    String newMessage = updatePrefix(ticketName.get(), currentMessage, ticketSystem, wrapLeft, wrapRight, issueKeyPosition);
+
+    // CommitMessage.getText() trims trailing whitespace, so compare rTrimmed to detect real changes
+    if (rTrim(newMessage).equals(currentMessage == null ? "" : rTrim(currentMessage))) {
+      return Optional.empty();
     }
 
-    return panel.getCommitMessage();
+    return Optional.of(newMessage);
   }
 
   static Optional<String> getTicket(TicketSystem ticketSystem, String branchName) {
diff --git a/src/test/java/ch/repnik/intellij/CommitPrefixCheckinHandlerTest.java b/src/test/java/ch/repnik/intellij/CommitPrefixCheckinHandlerTest.java
index 41912ba..9c9ff16 100644
--- a/src/test/java/ch/repnik/intellij/CommitPrefixCheckinHandlerTest.java
+++ b/src/test/java/ch/repnik/intellij/CommitPrefixCheckinHandlerTest.java
@@ -504,6 +504,45 @@ public void getTicketName_branchNameStartingWithDigit_returnsTicket(TicketNameTe
   }
 
 
+  static Stream<Arguments> calculateNewCommitMessage_messageUnchanged_returnsEmpty() {
+    CalculateMessageTester startTemplate = new CalculateMessageTester().withWrapLeft("").withWrapRight(": ").withIssueKeyPosition(Position.START);
+    CalculateMessageTester endTemplate = new CalculateMessageTester().withWrapLeft(": ").withWrapRight("").withIssueKeyPosition(Position.END);
+
+    return Stream.of(
+            Arguments.of(startTemplate.withTicketSystem(JIRA).withBranchName("main").withCurrentMessage("Some message")),
+            Arguments.of(startTemplate.withTicketSystem(JIRA).withBranchName("develop").withCurrentMessage("")),
+            Arguments.of(startTemplate.withTicketSystem(JIRA).withBranchName("feature/ABC-1234-app-not-working").withCurrentMessage("ABC-1234: This is my text")),
+            Arguments.of(startTemplate.withTicketSystem(JIRA).withBranchName("feature/ABC-1234-app-not-working").withCurrentMessage("ABC-1234:")),
+            Arguments.of(endTemplate.withTicketSystem(JIRA).withBranchName("feature/ABC-1234-app-not-working").withCurrentMessage("This is my text: ABC-1234")),
+            Arguments.of(startTemplate.withTicketSystem(OTHER).withBranchName("feature/5678-app-not-working").withCurrentMessage("5678: This is my text"))
+    );
+  }
+
+  @ParameterizedTest
+  @MethodSource
+  public void calculateNewCommitMessage_messageUnchanged_returnsEmpty(CalculateMessageTester tester) {
+    tester.calculate().assertEmpty();
+  }
+
+  static Stream<Arguments> calculateNewCommitMessage_messageChanged_returnsNewMessage() {
+    CalculateMessageTester startTemplate = new CalculateMessageTester().withWrapLeft("").withWrapRight(": ").withIssueKeyPosition(Position.START);
+    CalculateMessageTester endTemplate = new CalculateMessageTester().withWrapLeft(": ").withWrapRight("").withIssueKeyPosition(Position.END);
+
+    return Stream.of(
+            Arguments.of(startTemplate.withTicketSystem(JIRA).withBranchName("feature/ABC-1234-app-not-working").withCurrentMessage(null), "ABC-1234: "),
+            Arguments.of(startTemplate.withTicketSystem(JIRA).withBranchName("feature/ABC-1234-app-not-working").withCurrentMessage("XYXY-837292: This is my text"), "ABC-1234: This is my text"),
+            Arguments.of(endTemplate.withTicketSystem(JIRA).withBranchName("feature/ABC-1234-app-not-working").withCurrentMessage("This is my text: XYXY-837292"), "This is my text: ABC-1234"),
+            Arguments.of(startTemplate.withTicketSystem(OTHER).withBranchName("feature/5678-app-not-working").withCurrentMessage("1111: This is my text"), "5678: This is my text")
+    );
+  }
+
+  @ParameterizedTest
+  @MethodSource
+  public void calculateNewCommitMessage_messageChanged_returnsNewMessage(CalculateMessageTester tester, String expectedMessage) {
+    tester.calculate().assertMessage(expectedMessage);
+  }
+
+
 
   @With
   @AllArgsConstructor
@@ -572,4 +611,45 @@ void doAssertion(String expectedTicketName) {
       assertThat(actualTicketName.get(), is(expectedTicketName));
     }
   }
+
+
+  @With
+  @AllArgsConstructor
+  @NoArgsConstructor
+  static class CalculateMessageTester {
+
+    private TicketSystem ticketSystem;
+    private String branchName;
+    private String currentMessage;
+    private String wrapLeft;
+    private String wrapRight;
+    private Position issueKeyPosition;
+
+    CalculateMessageAsserter calculate() {
+      Optional<String> newMessage =
+              CommitPrefixCheckinHandler.calculateNewCommitMessage(
+                      ticketSystem, branchName, currentMessage, wrapLeft, wrapRight, issueKeyPosition);
+      return new CalculateMessageAsserter(newMessage);
+    }
+
+    @Override
+    public String toString() {
+      return String.format("%s, %s, %s", ticketSystem.toString(), branchName, currentMessage);
+    }
+  }
+
+  @RequiredArgsConstructor
+  static class CalculateMessageAsserter {
+
+    private final Optional<String> actualMessage;
+
+    void assertEmpty() {
+      assertThat(actualMessage.isPresent(), is(false));
+    }
+
+    void assertMessage(String expectedMessage) {
+      assertThat(actualMessage.isPresent(), is(true));
+      assertThat(actualMessage.get(), is(expectedMessage));
+    }
+  }
 }