diff --git a/src/applications/diviner/query/DivinerBookQuery.php b/src/applications/diviner/query/DivinerBookQuery.php
--- a/src/applications/diviner/query/DivinerBookQuery.php
+++ b/src/applications/diviner/query/DivinerBookQuery.php
@@ -133,7 +133,7 @@
         $this->phids);
     }
 
-    if (strlen($this->nameLike)) {
+    if (phutil_nonempty_string($this->nameLike)) {
       $where[] = qsprintf(
         $conn,
         'name LIKE %~',
@@ -147,7 +147,7 @@
         $this->names);
     }
 
-    if (strlen($this->namePrefix)) {
+    if (phutil_nonempty_string($this->namePrefix)) {
       $where[] = qsprintf(
         $conn,
         'name LIKE %>',
diff --git a/src/applications/diviner/storage/DivinerLiveSymbol.php b/src/applications/diviner/storage/DivinerLiveSymbol.php
--- a/src/applications/diviner/storage/DivinerLiveSymbol.php
+++ b/src/applications/diviner/storage/DivinerLiveSymbol.php
@@ -182,7 +182,7 @@
   public function setTitle($value) {
     $this->writeField('title', $value);
 
-    if (strlen($value)) {
+    if (phutil_nonempty_string($value)) {
       $slug = DivinerAtomRef::normalizeTitleString($value);
       $hash = PhabricatorHash::digestForIndex($slug);
       $this->titleSlugHash = $hash;
diff --git a/src/applications/diviner/workflow/DivinerGenerateWorkflow.php b/src/applications/diviner/workflow/DivinerGenerateWorkflow.php
--- a/src/applications/diviner/workflow/DivinerGenerateWorkflow.php
+++ b/src/applications/diviner/workflow/DivinerGenerateWorkflow.php
@@ -194,7 +194,7 @@
 
     $identifier = $args->getArg('repository');
     $repository = null;
-    if (strlen($identifier)) {
+    if (phutil_nonempty_string($identifier)) {
       $repository = id(new PhabricatorRepositoryQuery())
         ->setViewer(PhabricatorUser::getOmnipotentUser())
         ->withIdentifiers(array($identifier))