diff --git a/common/include/args.h b/common/include/args.h
index 8fd5c41e6..0bf74d521 100644
--- a/common/include/args.h
+++ b/common/include/args.h
@@ -25,7 +25,7 @@ COPYRIGHT 1993-1998 PARALLAX SOFTWARE CORPORATION.  ALL RIGHTS RESERVED.
 
 #pragma once
 
-#ifdef __cplusplus
+#include "dxxsconf.h"
 #include <cstdint>
 
 #ifdef OGL
@@ -168,5 +168,3 @@ static inline const char *PLAYER_DIRECTORY_STRING(const char *s)
 #define PLAYER_DIRECTORY_STRING(S)	((PLAYER_DIRECTORY_STRING)(PLAYER_DIRECTORY_TEXT S))
 }
 #endif
-
-#endif
diff --git a/common/include/ogl_init.h b/common/include/ogl_init.h
index 8eed9c5c8..2d8786c02 100644
--- a/common/include/ogl_init.h
+++ b/common/include/ogl_init.h
@@ -12,6 +12,7 @@
 #ifndef _OGL_INIT_H_ 
 #define _OGL_INIT_H_
 
+#include "dxxsconf.h"
 #ifdef _MSC_VER
 #include <windows.h>
 #include <stddef.h>
@@ -37,7 +38,6 @@
 # endif
 #endif
 
-#include "dxxsconf.h"
 #include "dsx-ns.h"
 #include "fwd-gr.h"
 #include "palette.h"
diff --git a/similar/arch/ogl/ogl.cpp b/similar/arch/ogl/ogl.cpp
index fe2ca13d5..5617853d4 100644
--- a/similar/arch/ogl/ogl.cpp
+++ b/similar/arch/ogl/ogl.cpp
@@ -10,6 +10,7 @@
  *
  */
 
+#include "dxxsconf.h"
 #include <stdexcept>
 #include <tuple>
 #ifdef _WIN32
diff --git a/similar/main/automap.cpp b/similar/main/automap.cpp
index c0b9d79c6..6a958b0d5 100644
--- a/similar/main/automap.cpp
+++ b/similar/main/automap.cpp
@@ -23,6 +23,7 @@ COPYRIGHT 1993-1999 PARALLAX SOFTWARE CORPORATION.  ALL RIGHTS RESERVED.
  *
  */
 
+#include "dxxsconf.h"
 #include <algorithm>
 #include <stdio.h>
 #include <stdlib.h>
diff --git a/similar/main/game.cpp b/similar/main/game.cpp
index 392c2a085..92dc7aee6 100644
--- a/similar/main/game.cpp
+++ b/similar/main/game.cpp
@@ -23,6 +23,7 @@ COPYRIGHT 1993-1999 PARALLAX SOFTWARE CORPORATION.  ALL RIGHTS RESERVED.
  *
  */
 
+#include "dxxsconf.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/similar/main/gameseq.cpp b/similar/main/gameseq.cpp
index 367b8c9ac..1c46e765f 100644
--- a/similar/main/gameseq.cpp
+++ b/similar/main/gameseq.cpp
@@ -23,6 +23,7 @@ COPYRIGHT 1993-1999 PARALLAX SOFTWARE CORPORATION.  ALL RIGHTS RESERVED.
  *
  */
 
+#include "dxxsconf.h"
 #include <cctype>
 #include <utility>
 #include <stdio.h>
diff --git a/similar/main/titles.cpp b/similar/main/titles.cpp
index ceebbb337..3beae6cb8 100644
--- a/similar/main/titles.cpp
+++ b/similar/main/titles.cpp
@@ -24,6 +24,7 @@ COPYRIGHT 1993-1999 PARALLAX SOFTWARE CORPORATION.  ALL RIGHTS RESERVED.
  */
 
 
+#include "dxxsconf.h"
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>