diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -187,7 +187,6 @@
     'ArcanistTimeWorkflow' => 'workflow/ArcanistTimeWorkflow.php',
     'ArcanistTodoWorkflow' => 'workflow/ArcanistTodoWorkflow.php',
     'ArcanistUSEnglishTranslation' => 'internationalization/ArcanistUSEnglishTranslation.php',
-    'ArcanistUncommittedChangesException' => 'exception/usage/ArcanistUncommittedChangesException.php',
     'ArcanistUnitConsoleRenderer' => 'unit/renderer/ArcanistUnitConsoleRenderer.php',
     'ArcanistUnitRenderer' => 'unit/renderer/ArcanistUnitRenderer.php',
     'ArcanistUnitTestEngine' => 'unit/engine/ArcanistUnitTestEngine.php',
@@ -372,7 +371,6 @@
     'ArcanistTimeWorkflow' => 'ArcanistPhrequentWorkflow',
     'ArcanistTodoWorkflow' => 'ArcanistWorkflow',
     'ArcanistUSEnglishTranslation' => 'PhutilTranslation',
-    'ArcanistUncommittedChangesException' => 'ArcanistUsageException',
     'ArcanistUnitConsoleRenderer' => 'ArcanistUnitRenderer',
     'ArcanistUnitTestableLintEngine' => 'ArcanistLintEngine',
     'ArcanistUnitWorkflow' => 'ArcanistWorkflow',
diff --git a/src/exception/usage/ArcanistUncommittedChangesException.php b/src/exception/usage/ArcanistUncommittedChangesException.php
deleted file mode 100644
--- a/src/exception/usage/ArcanistUncommittedChangesException.php
+++ /dev/null
@@ -1,4 +0,0 @@
-<?php
-
-final class ArcanistUncommittedChangesException
-  extends ArcanistUsageException {}
diff --git a/src/workflow/ArcanistDiffWorkflow.php b/src/workflow/ArcanistDiffWorkflow.php
--- a/src/workflow/ArcanistDiffWorkflow.php
+++ b/src/workflow/ArcanistDiffWorkflow.php
@@ -626,40 +626,18 @@
 
     if ($this->requiresWorkingCopy()) {
       $repository_api = $this->getRepositoryAPI();
-      try {
-        if ($this->getArgument('add-all')) {
-          $this->setCommitMode(self::COMMIT_ENABLE);
-        } else if ($this->getArgument('uncommitted')) {
-          $this->setCommitMode(self::COMMIT_DISABLE);
-        } else {
-          $this->setCommitMode(self::COMMIT_ALLOW);
-        }
-        if ($repository_api instanceof ArcanistSubversionAPI) {
-          $repository_api->limitStatusToPaths($this->getArgument('paths'));
-        }
-        if (!$this->getArgument('head')) {
-          $this->requireCleanWorkingCopy();
-        }
-      } catch (ArcanistUncommittedChangesException $ex) {
-        if ($repository_api instanceof ArcanistMercurialAPI) {
-          $use_dirty_changes = false;
-          if ($this->getArgument('uncommitted')) {
-            // OK.
-          } else {
-            $ok = phutil_console_confirm(
-              "You have uncommitted changes in your working copy. You can ".
-              "include them in the diff, or abort and deal with them. (Use ".
-              "'--uncommitted' to include them and skip this prompt.) ".
-              "Do you want to include uncommitted changes in the diff?");
-            if (!$ok) {
-              throw $ex;
-            }
-          }
-
-          $this->haveUncommittedChanges = true;
-        } else {
-          throw $ex;
-        }
+      if ($this->getArgument('add-all')) {
+        $this->setCommitMode(self::COMMIT_ENABLE);
+      } else if ($this->getArgument('uncommitted')) {
+        $this->setCommitMode(self::COMMIT_DISABLE);
+      } else {
+        $this->setCommitMode(self::COMMIT_ALLOW);
+      }
+      if ($repository_api instanceof ArcanistSubversionAPI) {
+        $repository_api->limitStatusToPaths($this->getArgument('paths'));
+      }
+      if (!$this->getArgument('head')) {
+        $this->requireCleanWorkingCopy();
       }
     }