diff --git a/src/afs/AIX/osi_prototypes.h b/src/afs/AIX/osi_prototypes.h
index c869dc0857..25f551258d 100644
--- a/src/afs/AIX/osi_prototypes.h
+++ b/src/afs/AIX/osi_prototypes.h
@@ -10,6 +10,9 @@
 #ifndef _OSI_PROTOTYPES_H_
 #define _OSI_PROTOTYPES_H_
 
+/* osi_file.c */
+extern afs_rwlock_t afs_xosi;
+
 /* osi_groups.c */
 extern void afs_aix_SetupPagRefCount(void);
 
diff --git a/src/afs/DARWIN/osi_prototypes.h b/src/afs/DARWIN/osi_prototypes.h
index ed68243c18..874a71b12d 100644
--- a/src/afs/DARWIN/osi_prototypes.h
+++ b/src/afs/DARWIN/osi_prototypes.h
@@ -14,6 +14,9 @@
 #ifndef _OSI_PROTO_H_
 #define _OSI_PROTO_H_
 
+/* osi_file.c */
+extern afs_rwlock_t afs_xosi;
+
 /* osi_misc.c */
 extern int osi_lookupname(char *aname, enum uio_seg seg, int followlink,
 	                  struct vnode **dirvpp, struct vnode **vpp);
diff --git a/src/afs/DUX/osi_prototypes.h b/src/afs/DUX/osi_prototypes.h
new file mode 100644
index 0000000000..4bc45e9e8b
--- /dev/null
+++ b/src/afs/DUX/osi_prototypes.h
@@ -0,0 +1,12 @@
+/*
+ * osi_prototypes.h
+ *
+ * Exported macos support routines.
+ */
+#ifndef _OSI_PROTO_H_
+#define _OSI_PROTO_H_
+
+/* osi_file.c */
+extern afs_rwlock_t afs_xosi;
+
+#endif /* _OSI_PROTO_H_ */
diff --git a/src/afs/FBSD/osi_prototypes.h b/src/afs/FBSD/osi_prototypes.h
index b6bac79193..f4aad3cb8a 100644
--- a/src/afs/FBSD/osi_prototypes.h
+++ b/src/afs/FBSD/osi_prototypes.h
@@ -14,6 +14,9 @@
 #ifndef _OSI_PROTO_H_
 #define _OSI_PROTO_H_
 
+/* osi_file.c */
+extern afs_rwlock_t afs_xosi;
+
 /* osi_misc.c */
 extern int osi_lookupname(char *aname, enum uio_seg seg, int followlink,
 	                  struct vnode **dirvpp, struct vnode **vpp);
diff --git a/src/afs/HPUX/osi_prototypes.h b/src/afs/HPUX/osi_prototypes.h
new file mode 100644
index 0000000000..4bc45e9e8b
--- /dev/null
+++ b/src/afs/HPUX/osi_prototypes.h
@@ -0,0 +1,12 @@
+/*
+ * osi_prototypes.h
+ *
+ * Exported macos support routines.
+ */
+#ifndef _OSI_PROTO_H_
+#define _OSI_PROTO_H_
+
+/* osi_file.c */
+extern afs_rwlock_t afs_xosi;
+
+#endif /* _OSI_PROTO_H_ */
diff --git a/src/afs/OBSD/osi_prototypes.h b/src/afs/OBSD/osi_prototypes.h
new file mode 100644
index 0000000000..4bc45e9e8b
--- /dev/null
+++ b/src/afs/OBSD/osi_prototypes.h
@@ -0,0 +1,12 @@
+/*
+ * osi_prototypes.h
+ *
+ * Exported macos support routines.
+ */
+#ifndef _OSI_PROTO_H_
+#define _OSI_PROTO_H_
+
+/* osi_file.c */
+extern afs_rwlock_t afs_xosi;
+
+#endif /* _OSI_PROTO_H_ */
diff --git a/src/afs/SOLARIS/osi_prototypes.h b/src/afs/SOLARIS/osi_prototypes.h
index 6219269c0c..1390222f30 100644
--- a/src/afs/SOLARIS/osi_prototypes.h
+++ b/src/afs/SOLARIS/osi_prototypes.h
@@ -10,6 +10,9 @@
 #ifndef _OSI_PROTOTYPES_H_
 #define _OSI_PROTOTYPES_H_
 
+/* osi_file.c */
+extern afs_rwlock_t afs_xosi;
+
 /* osi_vnodeops.c */
 int afs_putapage(struct vnode *vp, struct page *pages,
 #if	defined(AFS_SUN56_ENV)