diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 6c3f4de..4f0a147 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -97,6 +97,7 @@ target_compile_options(rusdoom PRIVATE
     -wx
     -wcd=303
     -j # treat char as signed
+    -ei # use 4 bytes for enum
 )
 
 install(TARGETS rusdoom RUNTIME