diff --git a/include/mdbtools.h b/include/mdbtools.h
index 6783d92..918ea23 100644
--- a/include/mdbtools.h
+++ b/include/mdbtools.h
@@ -268,17 +268,19 @@ typedef struct {
 	unsigned int  cur_pos;
 	unsigned char pg_buf[MDB_PGSIZE];
 	unsigned char alt_pg_buf[MDB_PGSIZE];
+	MdbFormatConstants *fmt;
+    char date_fmt[64];
+    const char *boolean_false_value;
+    const char *boolean_true_value;
 	unsigned int  num_catalog;
+
+    // Non-cloneable fields start here
 	GPtrArray	*catalog;
 	MdbBackend	*default_backend;
 	char		*backend_name;
 	struct S_MdbTableDef *relationships_table;
 	char        *relationships_values[5];
-	MdbFormatConstants *fmt;
 	MdbStatistics *stats;
-    char date_fmt[64];
-    const char *boolean_false_value;
-    const char *boolean_true_value;
     GHashTable *backends;
 #ifdef HAVE_ICONV
 	iconv_t	iconv_in;
diff --git a/src/libmdb/file.c b/src/libmdb/file.c
index 6f5f637..b88ea96 100644
--- a/src/libmdb/file.c
+++ b/src/libmdb/file.c
@@ -17,6 +17,7 @@
  */
 
 #include <inttypes.h>
+#include <stddef.h>
 #include "mdbtools.h"
 
 /*
@@ -323,18 +324,20 @@ MdbHandle *mdb_clone_handle(MdbHandle *mdb)
 	unsigned int i;
 
 	newmdb = (MdbHandle *) g_memdup(mdb, sizeof(MdbHandle));
-	newmdb->stats = NULL;
+
+	memset(newmdb + offsetof(MdbHandle, catalog), 0,
+			sizeof(MdbHandle) - offsetof(MdbHandle, catalog));
+
 	newmdb->catalog = g_ptr_array_new();
 	for (i=0;i<mdb->num_catalog;i++) {
 		entry = g_ptr_array_index(mdb->catalog,i);
 		data = g_memdup(entry,sizeof(MdbCatalogEntry));
+		data->mdb = newmdb;
 		data->props = NULL;
 		g_ptr_array_add(newmdb->catalog, data);
 	}
+
 	mdb_iconv_init(newmdb);
-	newmdb->backends = NULL;
-	newmdb->backend_name = NULL;
-	newmdb->default_backend = NULL;
 	mdb_set_default_backend(newmdb, mdb->backend_name);
 
 	if (mdb->f) {