diff --git a/polymer/eduke32/build/include/baselayer.h b/polymer/eduke32/build/include/baselayer.h
index faae51ecc..9e2c3f7df 100644
--- a/polymer/eduke32/build/include/baselayer.h
+++ b/polymer/eduke32/build/include/baselayer.h
@@ -2,6 +2,8 @@
 // for the Build Engine
 // by Jonathon Fowler (jf@jonof.id.au)
 
+#pragma once
+
 #ifndef baselayer_h_
 #define baselayer_h_
 
diff --git a/polymer/eduke32/build/include/build.h b/polymer/eduke32/build/include/build.h
index ba0357cca..5cc9eb731 100644
--- a/polymer/eduke32/build/include/build.h
+++ b/polymer/eduke32/build/include/build.h
@@ -5,6 +5,7 @@
 // This file has been modified from Ken Silverman's original release
 // by Jonathon Fowler (jf@jonof.id.au)
 
+#pragma once
 
 #ifndef build_h_
 #define build_h_
diff --git a/polymer/eduke32/build/include/compat.h b/polymer/eduke32/build/include/compat.h
index 07a3d4401..c33aa9677 100644
--- a/polymer/eduke32/build/include/compat.h
+++ b/polymer/eduke32/build/include/compat.h
@@ -2,6 +2,8 @@
 // certain build environments. It also levels the playing field caused
 // by different platforms.
 
+#pragma once
+
 #ifndef compat_h_
 #define compat_h_