diff --git a/src/workflow/ArcanistExportWorkflow.php b/src/workflow/ArcanistExportWorkflow.php
index 7e0aa497..0e9afb5a 100644
--- a/src/workflow/ArcanistExportWorkflow.php
+++ b/src/workflow/ArcanistExportWorkflow.php
@@ -103,11 +103,17 @@ EOTEXT
     if ($this->getArgument('revision')) {
       $source = self::SOURCE_REVISION;
       $requested++;
+
+      $source_id = $this->getArgument($source);
+      $this->sourceID = $this->normalizeRevisionID($source_id);
     }
     if ($this->getArgument('diff')) {
       $source = self::SOURCE_DIFF;
       $requested++;
+
+      $this->sourceID = $this->getArgument($source);
     }
+    $this->source = $source;
 
     if ($requested > 1) {
       throw new ArcanistUsageException(
@@ -115,8 +121,6 @@ EOTEXT
       "one change source.");
     }
 
-    $this->source = $source;
-    $this->sourceID = $this->getArgument($source);
 
     $format = null;
     $requested = 0;