diff --git a/src/applications/search/compiler/PhutilSearchQueryCompiler.php b/src/applications/search/compiler/PhutilSearchQueryCompiler.php
--- a/src/applications/search/compiler/PhutilSearchQueryCompiler.php
+++ b/src/applications/search/compiler/PhutilSearchQueryCompiler.php
@@ -103,7 +103,9 @@
 
   private function tokenizeQuery($query) {
     $maximum_bytes = 1024;
-
+    if ($query === null) {
+      $query = '';
+    }
     $query_bytes = strlen($query);
     if ($query_bytes > $maximum_bytes) {
       throw new PhutilSearchQueryCompilerSyntaxException(