diff --git a/src/afs/FBSD/osi_vfsops.c b/src/afs/FBSD/osi_vfsops.c
index 6044bbed17..8a979db6d7 100644
--- a/src/afs/FBSD/osi_vfsops.c
+++ b/src/afs/FBSD/osi_vfsops.c
@@ -18,7 +18,6 @@ struct mount *afs_globalVFS = NULL;
 int afs_pbuf_freecnt = -1;
 
 extern int Afs_xsetgroups();
-extern int afs_xioctl();
 
 static struct syscall_helper_data afs_syscalls[] = {
     {
diff --git a/src/afs/HPUX/osi_vfsops.c b/src/afs/HPUX/osi_vfsops.c
index 0ddc227c78..46faca7433 100644
--- a/src/afs/HPUX/osi_vfsops.c
+++ b/src/afs/HPUX/osi_vfsops.c
@@ -290,7 +290,7 @@ int afs_vfs_slot = -1;
 
 afsc_link()
 {
-    extern int Afs_syscall(), afs_xioctl(), Afs_xsetgroups();
+    extern int Afs_syscall(), Afs_xsetgroups();
 
     /* For now nothing special is required during AFS initialization. */
     AFS_STATCNT(afsc_link);
diff --git a/src/afs/LINUX/osi_vnodeops.c b/src/afs/LINUX/osi_vnodeops.c
index 08fccb1b2e..8aeeafa9b2 100644
--- a/src/afs/LINUX/osi_vnodeops.c
+++ b/src/afs/LINUX/osi_vnodeops.c
@@ -613,10 +613,6 @@ out1:
 }
 
 
-/* in afs_pioctl.c */
-extern int afs_xioctl(struct inode *ip, struct file *fp, unsigned int com,
-		      unsigned long arg);
-
 static long afs_unlocked_xioctl(struct file *fp, unsigned int com,
                                unsigned long arg) {
     return afs_xioctl(FILE_INODE(fp), fp, com, arg);
diff --git a/src/afs/NBSD/osi_kmod.c b/src/afs/NBSD/osi_kmod.c
index f6585651e2..eefaf5617c 100644
--- a/src/afs/NBSD/osi_kmod.c
+++ b/src/afs/NBSD/osi_kmod.c
@@ -44,7 +44,6 @@
 #include "afs/afsincludes.h"    /* Afs-based standard headers */
 
 extern int afs3_syscall(struct lwp *, const void *, register_t *);
-extern int afs_xioctl(struct lwp *, const void *, register_t *);
 extern int Afs_xsetgroups(struct lwp *, const void *, register_t *);
 
 #if !defined(AFS_NBSD60_ENV)
diff --git a/src/afs/NBSD/osi_vfsops.c b/src/afs/NBSD/osi_vfsops.c
index 7679ff1695..5032a1dd9e 100644
--- a/src/afs/NBSD/osi_vfsops.c
+++ b/src/afs/NBSD/osi_vfsops.c
@@ -110,7 +110,6 @@ VFS_PROTOS(afs);
 #ifndef AFS_NBSD60_ENV
 extern int sys_lkmnosys(struct lwp *, const void *, register_t *);
 extern int afs3_syscall(struct lwp *, const void *, register_t *);
-extern int afs_xioctl(struct lwp *, const void *, register_t *);
 extern int Afs_xsetgroups(struct lwp *, const void *, register_t *);
 static int afs_badcall(struct lwp *, const void *, register_t *);
 
diff --git a/src/afs/OBSD/osi_vfsops.c b/src/afs/OBSD/osi_vfsops.c
index 830906cc38..e7729261ea 100644
--- a/src/afs/OBSD/osi_vfsops.c
+++ b/src/afs/OBSD/osi_vfsops.c
@@ -108,7 +108,7 @@ NONINFRINGEMENT.
 /* from /usr/src/sys/kern/vfs_subr.c */
 extern void insmntque(struct vnode *, struct mount *);
 
-extern int sys_lkmnosys(), afs_xioctl(), Afs_xsetgroups();
+extern int sys_lkmnosys(), Afs_xsetgroups();
 
 static int lkmid = -1;
 static int afs_badcall(struct proc *p, void *xx, register_t * yy);
diff --git a/src/afs/SOLARIS/osi_vfsops.c b/src/afs/SOLARIS/osi_vfsops.c
index c6c9ddf565..f3f9bd33c9 100644
--- a/src/afs/SOLARIS/osi_vfsops.c
+++ b/src/afs/SOLARIS/osi_vfsops.c
@@ -389,7 +389,6 @@ afsinit(int fstype, char *dummy)
 afsinit(struct vfssw *vfsswp, int fstype)
 #endif
 {
-    extern int afs_xioctl();
     extern int afs_xsetgroups();
 
     AFS_STATCNT(afsinit);
diff --git a/src/afs/afs_prototypes.h b/src/afs/afs_prototypes.h
index 9b3b1afec9..d7894dd674 100644
--- a/src/afs/afs_prototypes.h
+++ b/src/afs/afs_prototypes.h
@@ -812,6 +812,23 @@ extern int afs_syscall_pioctl(char *path, unsigned int com, caddr_t cmarg,
 extern int HandleIoctl(struct vcache *avc, afs_int32 acom,
 		       struct afs_ioctl *adata);
 
+#if defined(AFS_SUN5_ENV)
+struct afs_ioctl_sys;
+extern int afs_xioctl(struct afs_ioctl_sys *uap, rval_t *rvp);
+#elif defined(AFS_LINUX_ENV)
+extern int afs_xioctl(struct inode *ip, struct file *fp, unsigned int com, unsigned long arg);
+#elif defined(AFS_DAWRIN_ENV) & !defined(AFS_DARWIN80)
+extern int afs_xioctl(afs_proc_t *p, struct ioctl_args *uap, register_t *retval);
+#elif defined(AFS_FBSD_ENV)
+extern int afs_xioctl(struct thread *td, struct ioctl_args *uap, register_t *retval);
+#elif defined(AFS_NBSD_ENV)
+extern int afs_xioctl(afs_proc_t *p, const struct sys_ioctl_args *uap, register_t *retval);
+#elif defined(AFS_XBSD_ENV)
+extern int afs_xioctl(afs_proc_t *p, const struct ioctl_args *uap, register_t *retval);
+#elif defined(UKERNEL)
+extern int afs_xioctl(void);
+#endif
+
 
 /* afs_segments.c */
 extern int afs_StoreAllSegments(struct vcache *avc,