diff --git a/scm-core/src/main/java/sonia/scm/repository/NoCommonHistoryException.java b/scm-core/src/main/java/sonia/scm/repository/NoCommonHistoryException.java
index e63f28cdce..ddb7793d20 100644
--- a/scm-core/src/main/java/sonia/scm/repository/NoCommonHistoryException.java
+++ b/scm-core/src/main/java/sonia/scm/repository/NoCommonHistoryException.java
@@ -8,7 +8,11 @@ import static java.util.Collections.emptyList;
 public class NoCommonHistoryException extends BadRequestException {
 
   public NoCommonHistoryException() {
-    super(emptyList(), "no common history");
+    this("no common history");
+  }
+
+  public NoCommonHistoryException(String message) {
+    super(emptyList(), message);
   }
 
   @Override
diff --git a/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitUtil.java b/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitUtil.java
index b769b98b18..d726b992ca 100644
--- a/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitUtil.java
+++ b/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitUtil.java
@@ -735,7 +735,8 @@ public final class GitUtil
       mergeBaseWalk.markStart(mergeBaseWalk.parseCommit(revision2));
       RevCommit ancestor = mergeBaseWalk.next();
       if (ancestor == null) {
-        throw new NoCommonHistoryException();
+        String msg = "revisions %s and %s are not related and therefore do not have a common ancestor";
+        throw new NoCommonHistoryException(String.format(msg, revision1.name(), revision2.name()));
       }
       return ancestor.getId();
     }