diff --git a/src/afs/SOLARIS/osi_machdep.h b/src/afs/SOLARIS/osi_machdep.h
index 1e17748805..9027a0e7ca 100644
--- a/src/afs/SOLARIS/osi_machdep.h
+++ b/src/afs/SOLARIS/osi_machdep.h
@@ -56,7 +56,23 @@ local_osi_Time()
 #undef afs_osi_Alloc_NoSleep
 extern void *afs_osi_Alloc_NoSleep(size_t size);
 
-#define osi_vnhold(avc, r)  do { VN_HOLD(AFSTOV(avc)); } while(0)
+#ifdef AFS_SUN58_ENV
+# define osi_vnhold(avc, r)  do {    \
+    struct vnode *vp = AFSTOV(avc); \
+    uint_t prevcount;               \
+                                    \
+    mutex_enter(&vp->v_lock);       \
+    prevcount = vp->v_count++;      \
+    mutex_exit(&vp->v_lock);        \
+                                    \
+    if (prevcount == 0) {           \
+	VFS_HOLD(afs_globalVFS);    \
+    }                               \
+} while(0)
+#else /* !AFS_SUN58_ENV */
+# define osi_vnhold(avc, r)  do { VN_HOLD(AFSTOV(avc)); } while(0)
+#endif /* !AFS_SUN58_ENV */
+
 #define gop_rdwr(rw,gp,base,len,offset,segflg,ioflag,ulimit,cr,aresid) \
   vn_rdwr((rw),(gp),(base),(len),(offset),(segflg),(ioflag),(ulimit),(cr),(aresid))
 #define gop_lookupname(fnamep,segflg,followlink,compvpp) \
diff --git a/src/afs/SOLARIS/osi_vcache.c b/src/afs/SOLARIS/osi_vcache.c
index 14a3828684..7435ed3ec5 100644
--- a/src/afs/SOLARIS/osi_vcache.c
+++ b/src/afs/SOLARIS/osi_vcache.c
@@ -67,4 +67,11 @@ osi_PostPopulateVCache(struct vcache *avc) {
     AFSTOV(avc)->v_op = afs_ops;
     AFSTOV(avc)->v_vfsp = afs_globalVFS;
     vSetType(avc, VREG);
+
+#ifdef AFS_SUN58_ENV
+    /* Normally we do this in osi_vnhold when we notice the ref count went from
+     * 0 -> 1. But if we just setup or reused a vcache, we set the refcount to
+     * 1 directly. So, we must explicitly VFS_HOLD here. */
+    VFS_HOLD(afs_globalVFS);
+#endif
 }
diff --git a/src/afs/SOLARIS/osi_vfsops.c b/src/afs/SOLARIS/osi_vfsops.c
index c474f8aea0..31e9007cf3 100644
--- a/src/afs/SOLARIS/osi_vfsops.c
+++ b/src/afs/SOLARIS/osi_vfsops.c
@@ -96,6 +96,20 @@ afs_unmount(struct vfs *afsp, afs_ucred_t *credp)
 	AFS_GUNLOCK();
 	return ENOTSUP;
     }
+
+    /* We should have one reference from the caller, and one reference for the
+     * root vnode; any more and someone is still referencing something */
+    if (afsp->vfs_count > 2) {
+	AFS_GUNLOCK();
+	return EBUSY;
+    }
+
+    /* The root vnode should have one ref for the mount; any more, and someone
+     * else is using the root vnode */
+    if (afs_globalVp && VREFCOUNT_GT(afs_globalVp, 1)) {
+	AFS_GUNLOCK();
+	return EBUSY;
+    }
 #endif /* AFS_SUN58_ENV */
 
     afs_globalVFS = 0;
diff --git a/src/afs/SOLARIS/osi_vnodeops.c b/src/afs/SOLARIS/osi_vnodeops.c
index f02d19f12e..0ec2e09b0b 100644
--- a/src/afs/SOLARIS/osi_vnodeops.c
+++ b/src/afs/SOLARIS/osi_vnodeops.c
@@ -1815,6 +1815,11 @@ afs_inactive(struct vcache *avc, afs_ucred_t *acred)
 	avc->opens = avc->execsOrWriters = 0;
 
     afs_InactiveVCache(avc, acred);
+
+#ifdef AFS_SUN58_ENV
+    VFS_RELE(afs_globalVFS);
+#endif
+
     return 0;
 }