diff --git a/tools/OILGen.cpp b/tools/OILGen.cpp
index 12f1408..00e1b4b 100644
--- a/tools/OILGen.cpp
+++ b/tools/OILGen.cpp
@@ -16,6 +16,7 @@
 
 #include <glog/logging.h>
 
+#include <cstdlib>
 #include <filesystem>
 #include <iostream>
 
@@ -77,6 +78,12 @@ int main(int argc, char* argv[]) {
   }
   fs::path primaryObject = argv[optind];
 
+  if ((setenv("DRGN_ENABLE_TYPE_ITERATOR", "1", 1)) < 0) {
+    std::cerr << "Failed to set environment variable\
+       DRGN_ENABLE_TYPE_ITERATOR\n";
+    exit(EXIT_FAILURE);
+  }
+
   OIGenerator oigen;
 
   oigen.setOutputPath(std::move(outputPath));