diff --git a/scripts/arcanist.php b/scripts/arcanist.php
index 6669b0b29..36be10531 100755
--- a/scripts/arcanist.php
+++ b/scripts/arcanist.php
@@ -522,9 +522,7 @@ function arcanist_load_libraries(
       if ($must_load) {
         throw new ArcanistUsageException($error);
       } else {
-        file_put_contents(
-          'php://stderr',
-          phutil_console_wrap('WARNING: '.$error."\n\n"));
+        fwrite(STDERR, phutil_console_wrap('WARNING: '.$error."\n\n"));
       }
     } catch (PhutilLibraryConflictException $ex) {
       if ($ex->getLibrary() != 'arcanist') {
diff --git a/src/parser/ArcanistBaseCommitParser.php b/src/parser/ArcanistBaseCommitParser.php
index e226b3340..a6a893183 100644
--- a/src/parser/ArcanistBaseCommitParser.php
+++ b/src/parser/ArcanistBaseCommitParser.php
@@ -48,7 +48,7 @@ private function tokenizeBaseCommitSpecification($raw_spec) {
 
   private function log($message) {
     if ($this->verbose) {
-      file_put_contents('php://stderr', $message."\n");
+      fwrite(STDERR, $message."\n");
     }
   }
 
diff --git a/src/workflow/ArcanistBaseWorkflow.php b/src/workflow/ArcanistBaseWorkflow.php
index 15031923c..ef21792e5 100644
--- a/src/workflow/ArcanistBaseWorkflow.php
+++ b/src/workflow/ArcanistBaseWorkflow.php
@@ -1097,7 +1097,7 @@ public function writeLocalArcConfig(array $config) {
    * @return void
    */
   protected function writeStatusMessage($msg) {
-    file_put_contents('php://stderr', $msg);
+    fwrite(STDERR, $msg);
   }
 
   protected function isHistoryImmutable() {
diff --git a/src/workflow/ArcanistDiffWorkflow.php b/src/workflow/ArcanistDiffWorkflow.php
index 1f9fabd9a..1eda21187 100644
--- a/src/workflow/ArcanistDiffWorkflow.php
+++ b/src/workflow/ArcanistDiffWorkflow.php
@@ -775,7 +775,7 @@ protected function generateChanges() {
     if ($is_raw) {
 
       if ($this->getArgument('raw')) {
-        file_put_contents('php://stderr', "Reading diff from stdin...\n");
+        fwrite(STDERR, "Reading diff from stdin...\n");
         $raw_diff = file_get_contents('php://stdin');
       } else if ($this->getArgument('raw-command')) {
         list($raw_diff) = execx($this->getArgument('raw-command'));