diff --git a/java/google/registry/tools/UpdateSmdCommand.java b/java/google/registry/tools/UpdateSmdCommand.java
index ea5455b49..195030d1b 100644
--- a/java/google/registry/tools/UpdateSmdCommand.java
+++ b/java/google/registry/tools/UpdateSmdCommand.java
@@ -57,6 +57,11 @@ final class UpdateSmdCommand implements RemoteApiCommand {
       required = true)
   private Path smdFile;
 
+  @Parameter(
+      names = "--reason",
+      description = "Special reason for the SMD update to record in the history entry.")
+  private String reason;
+
   @Override
   public void run() throws Exception {
     final EncodedSignedMark encodedSignedMark =
@@ -66,14 +71,15 @@ final class UpdateSmdCommand implements RemoteApiCommand {
         @Override
         public void vrun() {
           try {
-            updateSmd(id, encodedSignedMark);
+            updateSmd(id, encodedSignedMark, reason);
           } catch (EppException e) {
             throw new RuntimeException(e);
           }
         }});
   }
 
-  private void updateSmd(String applicationId, EncodedSignedMark encodedSignedMark)
+  private static void updateSmd(
+      String applicationId, EncodedSignedMark encodedSignedMark, String reason)
       throws EppException {
     ofy().assertInTransaction();
     DateTime now = ofy().getTransactionTime();
@@ -105,6 +111,7 @@ final class UpdateSmdCommand implements RemoteApiCommand {
         .setModificationTime(now)
         .setClientId(domainApplication.getCurrentSponsorClientId())
         .setBySuperuser(true)
+        .setReason("UpdateSmdCommand" + (reason != null ? ": " + reason : ""))
         .build();
 
     // Save entities to datastore.
diff --git a/javatests/google/registry/tools/UpdateSmdCommandTest.java b/javatests/google/registry/tools/UpdateSmdCommandTest.java
index 762dbfb82..caf5f67ba 100644
--- a/javatests/google/registry/tools/UpdateSmdCommandTest.java
+++ b/javatests/google/registry/tools/UpdateSmdCommandTest.java
@@ -77,7 +77,7 @@ public class UpdateSmdCommandTest extends CommandTestCase<UpdateSmdCommand> {
   public void testSuccess() throws Exception {
     DateTime before = new DateTime(UTC);
     String smdFile = writeToTmpFile(ACTIVE_SMD);
-    runCommand("--id=2-Q9JYB4C", "--smd=" + smdFile);
+    runCommand("--id=2-Q9JYB4C", "--smd=" + smdFile, "--reason=testing");
 
     EncodedSignedMark encodedSignedMark = TmchData.readEncodedSignedMark(ACTIVE_SMD);
     assertAboutApplications().that(reloadDomainApplication())
@@ -86,7 +86,9 @@ public class UpdateSmdCommandTest extends CommandTestCase<UpdateSmdCommand> {
         .hasLastEppUpdateClientId("TheRegistrar").and()
         .hasOnlyOneHistoryEntryWhich()
             .hasType(HistoryEntry.Type.DOMAIN_APPLICATION_UPDATE).and()
-            .hasClientId("TheRegistrar");
+            .hasClientId("TheRegistrar").and()
+            .hasMetadataReason("UpdateSmdCommand: testing").and()
+            .hasNoXml();
   }
 
   @Test