diff --git a/os/access.c b/os/access.c
index 6f6aec14f..ef6147f03 100644
--- a/os/access.c
+++ b/os/access.c
@@ -192,6 +192,7 @@ SOFTWARE.
 
 #include "xace.h"
 #include "rpcauth.h"
+#include "xdmcp.h"
 
 Bool defeatAccessControl = FALSE;
 
diff --git a/os/auth.c b/os/auth.c
index 49005f6b0..2518b5293 100644
--- a/os/auth.c
+++ b/os/auth.c
@@ -49,6 +49,7 @@ from The Open Group.
 #include   <stdlib.h>       /* for arc4random_buf() */
 
 #include "rpcauth.h"
+#include "xdmcp.h"
 
 struct protocol {
     unsigned short name_length;
diff --git a/os/connection.c b/os/connection.c
index 8d4b66061..d957ad661 100644
--- a/os/connection.c
+++ b/os/connection.c
@@ -117,6 +117,7 @@ SOFTWARE.
 #endif
 
 #include "probes.h"
+#include "xdmcp.h"
 
 struct ospoll   *server_poll;
 
diff --git a/os/osdep.h b/os/osdep.h
index a0e4d06ca..fb08d8588 100644
--- a/os/osdep.h
+++ b/os/osdep.h
@@ -169,32 +169,6 @@ extern int XdmAddCookie(AuthAddCArgs);
 extern int XdmFromID(AuthFromIDArgs);
 extern int XdmRemoveCookie(AuthRemCArgs);
 extern int XdmResetCookie(AuthRstCArgs);
-#endif
-
-#ifdef XDMCP
-/* in xdmcp.c */
-extern void XdmcpUseMsg(void);
-extern int XdmcpOptions(int argc, char **argv, int i);
-extern void XdmcpRegisterConnection(int type, const char *address, int addrlen);
-extern void XdmcpRegisterAuthorizations(void);
-extern void XdmcpRegisterAuthorization(const char *name, int namelen);
-extern void XdmcpInit(void);
-extern void XdmcpReset(void);
-extern void XdmcpOpenDisplay(int sock);
-extern void XdmcpCloseDisplay(int sock);
-extern void XdmcpRegisterAuthentication(const char *name,
-                                        int namelen,
-                                        const char *data,
-                                        int datalen,
-                                        ValidatorFunc Validator,
-                                        GeneratorFunc Generator,
-                                        AddAuthorFunc AddAuth);
-
-struct sockaddr_in;
-extern void XdmcpRegisterBroadcastAddress(const struct sockaddr_in *addr);
-#endif
-
-#ifdef HASXDMAUTH
 extern void XdmAuthenticationInit(const char *cookie, int cookie_length);
 #endif
 
diff --git a/os/utils.c b/os/utils.c
index 98f532d89..ddcfb629f 100644
--- a/os/utils.c
+++ b/os/utils.c
@@ -83,6 +83,7 @@ __stdcall unsigned long GetTickCount(void);
 #include <X11/fonts/libxfont2.h>
 #include "osdep.h"
 #include "bug.h"
+#include "xdmcp.h"
 #include "extension.h"
 #include <signal.h>
 #ifndef WIN32
diff --git a/os/xdmauth.c b/os/xdmauth.c
index ba446e013..aa1c113d2 100644
--- a/os/xdmauth.c
+++ b/os/xdmauth.c
@@ -45,6 +45,7 @@ from The Open Group.
 #include <X11/Xtrans/Xtrans.h>
 #include "os.h"
 #include "osdep.h"
+#include "xdmcp.h"
 #include "dixstruct.h"
 
 #ifdef HASXDMAUTH
diff --git a/os/xdmcp.c b/os/xdmcp.c
index 2b7255644..a264d96af 100644
--- a/os/xdmcp.c
+++ b/os/xdmcp.c
@@ -40,6 +40,7 @@
 #include <X11/Xmd.h>
 #include "misc.h"
 #include "osdep.h"
+#include "xdmcp.h"
 #include "input.h"
 #include "dixstruct.h"
 #include "opaque.h"
diff --git a/os/xdmcp.h b/os/xdmcp.h
new file mode 100644
index 000000000..e8b1a3c3e
--- /dev/null
+++ b/os/xdmcp.h
@@ -0,0 +1,27 @@
+#ifndef _XSERVER_OS_XDMCP_H
+#define _XSERVER_OS_XDMCP_H
+
+#include "osdep.h"
+
+/* in xdmcp.c */
+void XdmcpUseMsg(void);
+int XdmcpOptions(int argc, char **argv, int i);
+void XdmcpRegisterConnection(int type, const char *address, int addrlen);
+void XdmcpRegisterAuthorizations(void);
+void XdmcpRegisterAuthorization(const char *name, int namelen);
+void XdmcpInit(void);
+void XdmcpReset(void);
+void XdmcpOpenDisplay(int sock);
+void XdmcpCloseDisplay(int sock);
+void XdmcpRegisterAuthentication(const char *name,
+                                 int namelen,
+                                 const char *data,
+                                 int datalen,
+                                 ValidatorFunc Validator,
+                                 GeneratorFunc Generator,
+                                 AddAuthorFunc AddAuth);
+
+struct sockaddr_in;
+void XdmcpRegisterBroadcastAddress(const struct sockaddr_in *addr);
+
+#endif /* _XSERVER_OS_XDMCP_H */