diff --git a/src/vfs/local/local.c b/src/vfs/local/local.c
index 84ca56ed4..249864205 100644
--- a/src/vfs/local/local.c
+++ b/src/vfs/local/local.c
@@ -47,8 +47,10 @@
 
 /*** file scope variables ************************************************************************/
 
-static struct vfs_class vfs_local_ops;
+static struct vfs_s_subclass local_subclass;
+static struct vfs_class *vfs_local_ops = VFS_CLASS (&local_subclass);
 
+/* --------------------------------------------------------------------------------------------- */
 /*** file scope functions ************************************************************************/
 /* --------------------------------------------------------------------------------------------- */
 
@@ -422,35 +424,38 @@ local_lseek (void *data, off_t offset, int whence)
 void
 init_localfs (void)
 {
-    vfs_init_class (&vfs_local_ops, "localfs", VFS_LOCAL, NULL);
-    vfs_local_ops.which = local_which;
-    vfs_local_ops.open = local_open;
-    vfs_local_ops.close = local_close;
-    vfs_local_ops.read = local_read;
-    vfs_local_ops.write = local_write;
-    vfs_local_ops.opendir = local_opendir;
-    vfs_local_ops.readdir = local_readdir;
-    vfs_local_ops.closedir = local_closedir;
-    vfs_local_ops.stat = local_stat;
-    vfs_local_ops.lstat = local_lstat;
-    vfs_local_ops.fstat = local_fstat;
-    vfs_local_ops.chmod = local_chmod;
-    vfs_local_ops.chown = local_chown;
-    vfs_local_ops.utime = local_utime;
-    vfs_local_ops.readlink = local_readlink;
-    vfs_local_ops.symlink = local_symlink;
-    vfs_local_ops.link = local_link;
-    vfs_local_ops.unlink = local_unlink;
-    vfs_local_ops.rename = local_rename;
-    vfs_local_ops.chdir = local_chdir;
-    vfs_local_ops.ferrno = local_errno;
-    vfs_local_ops.lseek = local_lseek;
-    vfs_local_ops.mknod = local_mknod;
-    vfs_local_ops.getlocalcopy = local_getlocalcopy;
-    vfs_local_ops.ungetlocalcopy = local_ungetlocalcopy;
-    vfs_local_ops.mkdir = local_mkdir;
-    vfs_local_ops.rmdir = local_rmdir;
-    vfs_register_class (&vfs_local_ops);
+    /* NULLize vfs_s_subclass members */
+    memset (&local_subclass, 0, sizeof (local_subclass));
+
+    vfs_init_class (vfs_local_ops, "localfs", VFS_LOCAL, NULL);
+    vfs_local_ops->which = local_which;
+    vfs_local_ops->open = local_open;
+    vfs_local_ops->close = local_close;
+    vfs_local_ops->read = local_read;
+    vfs_local_ops->write = local_write;
+    vfs_local_ops->opendir = local_opendir;
+    vfs_local_ops->readdir = local_readdir;
+    vfs_local_ops->closedir = local_closedir;
+    vfs_local_ops->stat = local_stat;
+    vfs_local_ops->lstat = local_lstat;
+    vfs_local_ops->fstat = local_fstat;
+    vfs_local_ops->chmod = local_chmod;
+    vfs_local_ops->chown = local_chown;
+    vfs_local_ops->utime = local_utime;
+    vfs_local_ops->readlink = local_readlink;
+    vfs_local_ops->symlink = local_symlink;
+    vfs_local_ops->link = local_link;
+    vfs_local_ops->unlink = local_unlink;
+    vfs_local_ops->rename = local_rename;
+    vfs_local_ops->chdir = local_chdir;
+    vfs_local_ops->ferrno = local_errno;
+    vfs_local_ops->lseek = local_lseek;
+    vfs_local_ops->mknod = local_mknod;
+    vfs_local_ops->getlocalcopy = local_getlocalcopy;
+    vfs_local_ops->ungetlocalcopy = local_ungetlocalcopy;
+    vfs_local_ops->mkdir = local_mkdir;
+    vfs_local_ops->rmdir = local_rmdir;
+    vfs_register_class (vfs_local_ops);
 }
 
 /* --------------------------------------------------------------------------------------------- */
diff --git a/src/vfs/sfs/sfs.c b/src/vfs/sfs/sfs.c
index 19cd60021..63ebcc795 100644
--- a/src/vfs/sfs/sfs.c
+++ b/src/vfs/sfs/sfs.c
@@ -102,7 +102,8 @@ typedef struct cachedfile
 
 static GSList *head;
 
-static struct vfs_class vfs_sfs_ops;
+static struct vfs_s_subclass sfs_subclass;
+static struct vfs_class *vfs_sfs_ops = VFS_CLASS (&sfs_subclass);
 
 static int sfs_no = 0;
 static char *sfs_prefix[MAXFS];
@@ -235,7 +236,7 @@ sfs_redirect (const vfs_path_t * vpath)
     if (cur != NULL)
     {
         cf = (cachedfile *) cur->data;
-        vfs_stamp (&vfs_sfs_ops, cf);
+        vfs_stamp (vfs_sfs_ops, cf);
         return cf->cache;
     }
 
@@ -254,7 +255,7 @@ sfs_redirect (const vfs_path_t * vpath)
         head = g_slist_prepend (head, cf);
         vfs_path_free (cache_vpath);
 
-        vfs_stamp_create (&vfs_sfs_ops, (cachedfile *) head->data);
+        vfs_stamp_create (vfs_sfs_ops, (cachedfile *) head->data);
         return cf->cache;
     }
 
@@ -549,29 +550,32 @@ sfs_which (struct vfs_class *me, const char *path)
 void
 init_sfs (void)
 {
-    vfs_init_class (&vfs_sfs_ops, "sfs", VFS_UNKNOWN, NULL);
-    vfs_sfs_ops.init = sfs_init;
-    vfs_sfs_ops.done = sfs_done;
-    vfs_sfs_ops.fill_names = sfs_fill_names;
-    vfs_sfs_ops.which = sfs_which;
-    vfs_sfs_ops.open = sfs_open;
-    vfs_sfs_ops.close = local_close;
-    vfs_sfs_ops.read = local_read;
-    vfs_sfs_ops.stat = sfs_stat;
-    vfs_sfs_ops.lstat = sfs_lstat;
-    vfs_sfs_ops.fstat = local_fstat;
-    vfs_sfs_ops.chmod = sfs_chmod;
-    vfs_sfs_ops.chown = sfs_chown;
-    vfs_sfs_ops.utime = sfs_utime;
-    vfs_sfs_ops.readlink = sfs_readlink;
-    vfs_sfs_ops.ferrno = local_errno;
-    vfs_sfs_ops.lseek = local_lseek;
-    vfs_sfs_ops.getid = sfs_getid;
-    vfs_sfs_ops.nothingisopen = sfs_nothingisopen;
-    vfs_sfs_ops.free = sfs_free;
-    vfs_sfs_ops.getlocalcopy = sfs_getlocalcopy;
-    vfs_sfs_ops.ungetlocalcopy = sfs_ungetlocalcopy;
-    vfs_register_class (&vfs_sfs_ops);
+    /* NULLize vfs_s_subclass members */
+    memset (&sfs_subclass, 0, sizeof (sfs_subclass));
+
+    vfs_init_class (vfs_sfs_ops, "sfs", VFS_UNKNOWN, NULL);
+    vfs_sfs_ops->init = sfs_init;
+    vfs_sfs_ops->done = sfs_done;
+    vfs_sfs_ops->fill_names = sfs_fill_names;
+    vfs_sfs_ops->which = sfs_which;
+    vfs_sfs_ops->open = sfs_open;
+    vfs_sfs_ops->close = local_close;
+    vfs_sfs_ops->read = local_read;
+    vfs_sfs_ops->stat = sfs_stat;
+    vfs_sfs_ops->lstat = sfs_lstat;
+    vfs_sfs_ops->fstat = local_fstat;
+    vfs_sfs_ops->chmod = sfs_chmod;
+    vfs_sfs_ops->chown = sfs_chown;
+    vfs_sfs_ops->utime = sfs_utime;
+    vfs_sfs_ops->readlink = sfs_readlink;
+    vfs_sfs_ops->ferrno = local_errno;
+    vfs_sfs_ops->lseek = local_lseek;
+    vfs_sfs_ops->getid = sfs_getid;
+    vfs_sfs_ops->nothingisopen = sfs_nothingisopen;
+    vfs_sfs_ops->free = sfs_free;
+    vfs_sfs_ops->getlocalcopy = sfs_getlocalcopy;
+    vfs_sfs_ops->ungetlocalcopy = sfs_ungetlocalcopy;
+    vfs_register_class (vfs_sfs_ops);
 }
 
 /* --------------------------------------------------------------------------------------------- */
diff --git a/src/vfs/smbfs/smbfs.c b/src/vfs/smbfs/smbfs.c
index 56e8cde1a..a5639e3c1 100644
--- a/src/vfs/smbfs/smbfs.c
+++ b/src/vfs/smbfs/smbfs.c
@@ -38,6 +38,7 @@
 
 #include <stdio.h>
 #include <sys/types.h>
+#include <string.h>             /* memset() */
 
 #undef USE_NCURSES              /* Don't include *curses.h */
 #undef USE_NCURSESW
@@ -138,7 +139,8 @@ static gboolean got_pass = FALSE;
 static pstring password;
 static pstring username;
 
-static struct vfs_class vfs_smbfs_ops;
+static struct vfs_s_subclass smbfs_subclass;
+static struct vfs_class *vfs_smbfs_ops = VFS_CLASS (&smbfs_subclass);
 
 static struct _smbfs_connection
 {
@@ -2240,36 +2242,39 @@ init_smbfs (void)
 {
     tcp_init ();
 
-    vfs_init_class (&vfs_smbfs_ops, "smbfs", VFS_NOLINKS, "smb");
-    vfs_smbfs_ops.init = smbfs_init;
-    vfs_smbfs_ops.fill_names = smbfs_fill_names;
-    vfs_smbfs_ops.open = smbfs_open;
-    vfs_smbfs_ops.close = smbfs_close;
-    vfs_smbfs_ops.read = smbfs_read;
-    vfs_smbfs_ops.write = smbfs_write;
-    vfs_smbfs_ops.opendir = smbfs_opendir;
-    vfs_smbfs_ops.readdir = smbfs_readdir;
-    vfs_smbfs_ops.closedir = smbfs_closedir;
-    vfs_smbfs_ops.stat = smbfs_stat;
-    vfs_smbfs_ops.lstat = smbfs_lstat;
-    vfs_smbfs_ops.fstat = smbfs_fstat;
-    vfs_smbfs_ops.chmod = smbfs_chmod;
-    vfs_smbfs_ops.chown = smbfs_chown;
-    vfs_smbfs_ops.utime = smbfs_utime;
-    vfs_smbfs_ops.readlink = smbfs_readlink;
-    vfs_smbfs_ops.symlink = smbfs_symlink;
-    vfs_smbfs_ops.link = smbfs_link;
-    vfs_smbfs_ops.unlink = smbfs_unlink;
-    vfs_smbfs_ops.rename = smbfs_rename;
-    vfs_smbfs_ops.chdir = smbfs_chdir;
-    vfs_smbfs_ops.ferrno = smbfs_errno;
-    vfs_smbfs_ops.lseek = smbfs_lseek;
-    vfs_smbfs_ops.mknod = smbfs_mknod;
-    vfs_smbfs_ops.free = smbfs_free;
-    vfs_smbfs_ops.mkdir = smbfs_mkdir;
-    vfs_smbfs_ops.rmdir = smbfs_rmdir;
-    vfs_smbfs_ops.setctl = smbfs_setctl;
-    vfs_register_class (&vfs_smbfs_ops);
+    /* NULLize vfs_s_subclass members */
+    memset (&smbfs_subclass, 0, sizeof (smbfs_subclass));
+
+    vfs_init_class (vfs_smbfs_ops, "smbfs", VFS_NOLINKS, "smb");
+    vfs_smbfs_ops->init = smbfs_init;
+    vfs_smbfs_ops->fill_names = smbfs_fill_names;
+    vfs_smbfs_ops->open = smbfs_open;
+    vfs_smbfs_ops->close = smbfs_close;
+    vfs_smbfs_ops->read = smbfs_read;
+    vfs_smbfs_ops->write = smbfs_write;
+    vfs_smbfs_ops->opendir = smbfs_opendir;
+    vfs_smbfs_ops->readdir = smbfs_readdir;
+    vfs_smbfs_ops->closedir = smbfs_closedir;
+    vfs_smbfs_ops->stat = smbfs_stat;
+    vfs_smbfs_ops->lstat = smbfs_lstat;
+    vfs_smbfs_ops->fstat = smbfs_fstat;
+    vfs_smbfs_ops->chmod = smbfs_chmod;
+    vfs_smbfs_ops->chown = smbfs_chown;
+    vfs_smbfs_ops->utime = smbfs_utime;
+    vfs_smbfs_ops->readlink = smbfs_readlink;
+    vfs_smbfs_ops->symlink = smbfs_symlink;
+    vfs_smbfs_ops->link = smbfs_link;
+    vfs_smbfs_ops->unlink = smbfs_unlink;
+    vfs_smbfs_ops->rename = smbfs_rename;
+    vfs_smbfs_ops->chdir = smbfs_chdir;
+    vfs_smbfs_ops->ferrno = smbfs_errno;
+    vfs_smbfs_ops->lseek = smbfs_lseek;
+    vfs_smbfs_ops->mknod = smbfs_mknod;
+    vfs_smbfs_ops->free = smbfs_free;
+    vfs_smbfs_ops->mkdir = smbfs_mkdir;
+    vfs_smbfs_ops->rmdir = smbfs_rmdir;
+    vfs_smbfs_ops->setctl = smbfs_setctl;
+    vfs_register_class (vfs_smbfs_ops);
 }
 
 /* --------------------------------------------------------------------------------------------- */
diff --git a/src/vfs/undelfs/undelfs.c b/src/vfs/undelfs/undelfs.c
index cbd7f95bc..79c23b617 100644
--- a/src/vfs/undelfs/undelfs.c
+++ b/src/vfs/undelfs/undelfs.c
@@ -48,6 +48,7 @@
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>             /* memset() */
 
 #ifdef HAVE_EXT2FS_EXT2_FS_H
 #include <ext2fs/ext2_fs.h>
@@ -131,7 +132,8 @@ static const char *undelfserr = N_("undelfs: error");
 static int readdir_ptr;
 static int undelfs_usage;
 
-static struct vfs_class vfs_undelfs_ops;
+static struct vfs_s_subclass undelfs_subclass;
+static struct vfs_class *vfs_undelfs_ops = VFS_CLASS (&undelfs_subclass);
 
 /* --------------------------------------------------------------------------------------------- */
 /*** file scope functions ************************************************************************/
@@ -823,23 +825,26 @@ com_err (const char *whoami, long err_code, const char *fmt, ...)
 void
 init_undelfs (void)
 {
-    vfs_init_class (&vfs_undelfs_ops, "undelfs", VFS_UNKNOWN, "undel");
-    vfs_undelfs_ops.init = undelfs_init;
-    vfs_undelfs_ops.open = undelfs_open;
-    vfs_undelfs_ops.close = undelfs_close;
-    vfs_undelfs_ops.read = undelfs_read;
-    vfs_undelfs_ops.opendir = undelfs_opendir;
-    vfs_undelfs_ops.readdir = undelfs_readdir;
-    vfs_undelfs_ops.closedir = undelfs_closedir;
-    vfs_undelfs_ops.stat = undelfs_stat;
-    vfs_undelfs_ops.lstat = undelfs_lstat;
-    vfs_undelfs_ops.fstat = undelfs_fstat;
-    vfs_undelfs_ops.chdir = undelfs_chdir;
-    vfs_undelfs_ops.lseek = undelfs_lseek;
-    vfs_undelfs_ops.getid = undelfs_getid;
-    vfs_undelfs_ops.nothingisopen = undelfs_nothingisopen;
-    vfs_undelfs_ops.free = undelfs_free;
-    vfs_register_class (&vfs_undelfs_ops);
+    /* NULLize vfs_s_subclass members */
+    memset (&undelfs_subclass, 0, sizeof (undelfs_subclass));
+
+    vfs_init_class (vfs_undelfs_ops, "undelfs", VFS_UNKNOWN, "undel");
+    vfs_undelfs_ops->init = undelfs_init;
+    vfs_undelfs_ops->open = undelfs_open;
+    vfs_undelfs_ops->close = undelfs_close;
+    vfs_undelfs_ops->read = undelfs_read;
+    vfs_undelfs_ops->opendir = undelfs_opendir;
+    vfs_undelfs_ops->readdir = undelfs_readdir;
+    vfs_undelfs_ops->closedir = undelfs_closedir;
+    vfs_undelfs_ops->stat = undelfs_stat;
+    vfs_undelfs_ops->lstat = undelfs_lstat;
+    vfs_undelfs_ops->fstat = undelfs_fstat;
+    vfs_undelfs_ops->chdir = undelfs_chdir;
+    vfs_undelfs_ops->lseek = undelfs_lseek;
+    vfs_undelfs_ops->getid = undelfs_getid;
+    vfs_undelfs_ops->nothingisopen = undelfs_nothingisopen;
+    vfs_undelfs_ops->free = undelfs_free;
+    vfs_register_class (vfs_undelfs_ops);
 }
 
 /* --------------------------------------------------------------------------------------------- */
diff --git a/tests/lib/vfs/current_dir.c b/tests/lib/vfs/current_dir.c
index b2813335d..0bc4192d8 100644
--- a/tests/lib/vfs/current_dir.c
+++ b/tests/lib/vfs/current_dir.c
@@ -27,13 +27,16 @@
 
 #include "tests/mctest.h"
 
+#include <string.h>             /* memset() */
+
 #include "lib/global.h"
 #include "lib/strutil.h"
 #include "lib/vfs/xdirentry.h"
 
 #include "src/vfs/local/local.c"
 
-static struct vfs_class vfs_test_ops;
+static struct vfs_s_subclass vfs_test_subclass;
+static struct vfs_class *vfs_test_ops = VFS_CLASS (&vfs_test_subclass);
 
 /* --------------------------------------------------------------------------------------------- */
 
@@ -58,8 +61,9 @@ setup (void)
     init_localfs ();
     vfs_setup_work_dir ();
 
-    vfs_init_class (&vfs_test_ops, "testfs", VFS_UNKNOWN, "test");
-    vfs_test_ops.chdir = test_chdir;
+    memset (&vfs_test_subclass, 0, sizeof (vfs_test_subclass));
+    vfs_init_class (vfs_test_ops, "testfs", VFS_UNKNOWN, "test");
+    vfs_test_ops->chdir = test_chdir;
 }
 
 /* --------------------------------------------------------------------------------------------- */
@@ -150,8 +154,8 @@ START_PARAMETRIZED_TEST (test_cd, test_cd_ds)
     /* given */
     vfs_path_t *vpath;
 
-    vfs_test_ops.flags = data->input_class_flags;
-    vfs_register_class (&vfs_test_ops);
+    vfs_test_ops->flags = data->input_class_flags;
+    vfs_register_class (vfs_test_ops);
 
     vfs_set_raw_current_dir (vfs_path_from_str (data->input_initial_path));
 
@@ -170,7 +174,7 @@ START_PARAMETRIZED_TEST (test_cd, test_cd_ds)
     }
     vfs_path_free (vpath);
 
-    vfs_unregister_class (&vfs_test_ops);
+    vfs_unregister_class (vfs_test_ops);
 }
 /* *INDENT-OFF* */
 END_PARAMETRIZED_TEST
diff --git a/tests/lib/vfs/relative_cd.c b/tests/lib/vfs/relative_cd.c
index 417cb0a29..2d140a10f 100644
--- a/tests/lib/vfs/relative_cd.c
+++ b/tests/lib/vfs/relative_cd.c
@@ -26,6 +26,8 @@
 
 #include "tests/mctest.h"
 
+#include <string.h>             /* memset() */
+
 #include "lib/strutil.h"
 #include "lib/vfs/xdirentry.h"
 #include "lib/vfs/path.h"
@@ -33,7 +35,8 @@
 #include "src/vfs/local/local.c"
 
 
-static struct vfs_class vfs_test_ops1;
+static struct vfs_s_subclass vfs_test_subclass1;
+static struct vfs_class *vfs_test_ops1 = VFS_CLASS (&vfs_test_subclass1);
 
 static int test_chdir (const vfs_path_t * vpath);
 
@@ -76,13 +79,14 @@ setup (void)
     init_localfs ();
     vfs_setup_work_dir ();
 
-    vfs_init_class (&vfs_test_ops1, "testfs1", VFS_NOLINKS | VFS_REMOTE, "test1");
-    vfs_test_ops1.chdir = test_chdir;
-    vfs_register_class (&vfs_test_ops1);
+    memset (&vfs_test_subclass1, 0, sizeof (vfs_test_subclass1));
+    vfs_init_class (vfs_test_ops1, "testfs1", VFS_NOLINKS | VFS_REMOTE, "test1");
+    vfs_test_ops1->chdir = test_chdir;
+    vfs_register_class (vfs_test_ops1);
 
     mc_global.sysconfig_dir = (char *) TEST_SHARE_DIR;
 
-    vfs_local_ops.chdir = test_chdir;
+    vfs_local_ops->chdir = test_chdir;
 
     test_chdir__init ();
 }
diff --git a/tests/lib/vfs/vfs_path_string_convert.c b/tests/lib/vfs/vfs_path_string_convert.c
index 266664f94..8fe1690bd 100644
--- a/tests/lib/vfs/vfs_path_string_convert.c
+++ b/tests/lib/vfs/vfs_path_string_convert.c
@@ -107,7 +107,7 @@ static const struct test_from_to_string_ds
         "/",
         "/",
         1,
-        &vfs_local_ops
+        VFS_CLASS (&local_subclass)
     },
     { /* 2. */
         "/test1://bla-bla/some/path/test2://user:passwd@some.host:1234/bla-bla/some/path/test3://111/22/33",