diff --git a/cpp/ql/src/Security/CWE/CWE-428/UnsafeCreateProcessCall.ql b/cpp/ql/src/Security/CWE/CWE-428/UnsafeCreateProcessCall.ql
index 1518c6c1f0f0..c32ce5aae527 100644
--- a/cpp/ql/src/Security/CWE/CWE-428/UnsafeCreateProcessCall.ql
+++ b/cpp/ql/src/Security/CWE/CWE-428/UnsafeCreateProcessCall.ql
@@ -68,7 +68,7 @@ class NullAppNameCreateProcessFunctionConfiguration extends DataFlow::Configurat
   }
 
   override predicate isSource(DataFlow::Node source) {
-    nullValue(source.asExpr()) 
+    source.asExpr() instanceof NullValue
   }
 
   override predicate isSink(DataFlow::Node sink) {