1 files changed, 2 insertions, 2 deletions
diff --git a/src/Search/FTSLogicOp.php b/src/Search/FTSLogicOp.php
index 452f63b..5b8b738 100644
--- a/src/Search/FTSLogicOp.php
+++ b/src/Search/FTSLogicOp.php
@@ -33,8 +33,8 @@ class FTSLogicOp extends AbstractFTSExpr
 
     protected function fts4Query(): string
     {
+        assert(isset(self::FTSOPS[$this->op]));
         $ftsop = self::FTSOPS[$this->op];
-        assert($ftsop);
 
         return "({$this->a->fts4Query()} {$ftsop} {$this->b->fts4Query()})";
     }
@@ -43,4 +43,4 @@ class FTSLogicOp extends AbstractFTSExpr
     {
         return "({$this->a->toString()} FTS-{$this->op} {$this->b->toString()})";
     }
-}
-\ No newline at end of file
+}