diff --git a/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/RevId.java b/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/RevId.java
index d04f8e6..5474707 100644
--- a/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/RevId.java
+++ b/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/RevId.java
@@ -18,6 +18,7 @@
 
 /** A revision identifier for a file or a change. */
 public final class RevId {
+  public static final int ABBREV_LEN = 7;
   public static final int LEN = 40;
 
   @Column(id = 1, length = LEN)
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/git/validators/CommitValidators.java b/gerrit-server/src/main/java/com/google/gerrit/server/git/validators/CommitValidators.java
index 630dd32..02af281 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/git/validators/CommitValidators.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/git/validators/CommitValidators.java
@@ -26,6 +26,7 @@
 import com.google.gerrit.extensions.registration.DynamicSet;
 import com.google.gerrit.reviewdb.client.Account;
 import com.google.gerrit.reviewdb.client.RefNames;
+import com.google.gerrit.reviewdb.client.RevId;
 import com.google.gerrit.server.GerritPersonIdent;
 import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.account.WatchConfig;
@@ -202,7 +203,6 @@
   }
 
   public static class ChangeIdValidator implements CommitValidationListener {
-    private static final int SHA1_LENGTH = 7;
     private static final String CHANGE_ID_PREFIX = FooterConstants.CHANGE_ID.getName() + ":";
     private static final String MISSING_CHANGE_ID_MSG =
         "[%s] missing " + FooterConstants.CHANGE_ID.getName() + " in commit message footer";
@@ -245,7 +245,7 @@
       RevCommit commit = receiveEvent.commit;
       List<CommitValidationMessage> messages = new ArrayList<>();
       List<String> idList = commit.getFooterLines(FooterConstants.CHANGE_ID);
-      String sha1 = commit.abbreviate(SHA1_LENGTH).name();
+      String sha1 = commit.abbreviate(RevId.ABBREV_LEN).name();
 
       if (idList.isEmpty()) {
         if (projectControl.getProjectState().isRequireChangeID()) {