diff --git a/dtool/src/dtoolutil/executionEnvironment.cxx b/dtool/src/dtoolutil/executionEnvironment.cxx
index 96ae7fd147..603d3ea4f1 100644
--- a/dtool/src/dtoolutil/executionEnvironment.cxx
+++ b/dtool/src/dtoolutil/executionEnvironment.cxx
@@ -223,6 +223,8 @@ ns_has_environment_variable(const string &var) const {
 
 #ifndef PREREAD_ENVIRONMENT
   return getenv(var.c_str()) != nullptr;
+#else
+  return false;
 #endif
 }