diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/change/GetPatch.java b/gerrit-server/src/main/java/com/google/gerrit/server/change/GetPatch.java
index 3c4d79d057..a13e7be916 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/change/GetPatch.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/change/GetPatch.java
@@ -167,7 +167,7 @@ public class GetPatch implements RestReadView<RevisionResource> {
 
   private static String fileName(RevWalk rw, RevCommit commit)
       throws IOException {
-    AbbreviatedObjectId id = rw.getObjectReader().abbreviate(commit, 8);
+    AbbreviatedObjectId id = rw.getObjectReader().abbreviate(commit, 7);
     return id.name() + ".diff";
   }
 }