diff --git a/src/aphront/sink/AphrontPHPHTTPSink.php b/src/aphront/sink/AphrontPHPHTTPSink.php
index 2504aea037..4953b6e610 100644
--- a/src/aphront/sink/AphrontPHPHTTPSink.php
+++ b/src/aphront/sink/AphrontPHPHTTPSink.php
@@ -1,35 +1,36 @@
 <?php
 
 /**
  * Concrete HTTP sink which uses "echo" and "header()" to emit data.
  */
 final class AphrontPHPHTTPSink extends AphrontHTTPSink {
 
   protected function emitHTTPStatus($code, $message = '') {
     if ($code != 200) {
       $header = "HTTP/1.0 {$code}";
       if (strlen($message)) {
         $header .= " {$message}";
       }
       header($header);
     }
   }
 
   protected function emitHeader($name, $value) {
     header("{$name}: {$value}", $replace = false);
   }
 
   protected function emitData($data) {
     echo $data;
 
-    // Try to push the data to the browser. This has a lot of caveats around
-    // browser buffering and display behavior, but approximately works most
-    // of the time.
-    flush();
+    // NOTE: We don't call flush() here because it breaks HTTPS under Apache.
+    // See T7620 for discussion. Even without an explicit flush, PHP appears to
+    // have reasonable behavior here: the echo will block if internal buffers
+    // are full, and data will be sent to the client once enough of it has
+    // been buffered.
   }
 
   protected function isWritable() {
     return !connection_aborted();
   }
 
 }