diff --git a/dlls/twain/capability.c b/dlls/twain/capability.c
index fb0fdfa29f2..5f3af57ba43 100644
--- a/dlls/twain/capability.c
+++ b/dlls/twain/capability.c
@@ -19,6 +19,8 @@
 #define NONAMELESSUNION
 #define NONAMELESSSTRUCT
 
+#include "config.h"
+
 #include <stdarg.h>
 
 #include "windef.h"
diff --git a/dlls/twain/ds_audio.c b/dlls/twain/ds_audio.c
index a9c966a7670..105c4b77789 100644
--- a/dlls/twain/ds_audio.c
+++ b/dlls/twain/ds_audio.c
@@ -17,7 +17,7 @@
  */
 
 #include "twain.h"
-#include "twain_i.h"
+
 #include "wine/debug.h"
 
 WINE_DEFAULT_DEBUG_CHANNEL(twain);
@@ -48,4 +48,3 @@ TW_UINT16 TWAIN_AudioNativeXferGet (pTW_IDENTITY pOrigin, pTW_IDENTITY pDest,
 
     return TWRC_FAILURE;
 }
-
diff --git a/dlls/twain/twain16_main.c b/dlls/twain/twain16_main.c
index fa5aa5af57e..dc80440d063 100644
--- a/dlls/twain/twain16_main.c
+++ b/dlls/twain/twain16_main.c
@@ -18,6 +18,8 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
+#include "config.h"
+
 #include <stdarg.h>
 
 #include "windef.h"
diff --git a/dlls/twain/twain32_main.c b/dlls/twain/twain32_main.c
index e4cf857866a..e34588c6d8d 100644
--- a/dlls/twain/twain32_main.c
+++ b/dlls/twain/twain32_main.c
@@ -18,6 +18,8 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
+#include "config.h"
+
 #include <stdarg.h>
 
 #include "windef.h"
diff --git a/dlls/twain/twain_i.h b/dlls/twain/twain_i.h
index 118f557f2d3..e7be1cc1b70 100644
--- a/dlls/twain/twain_i.h
+++ b/dlls/twain/twain_i.h
@@ -19,6 +19,10 @@
 #ifndef _TWAIN32_H
 #define _TWAIN32_H
 
+#ifndef __WINE_CONFIG_H
+# error You must include config.h first
+#endif
+
 #ifdef HAVE_SANE
 # include <sane/sane.h>
 #endif