diff --git a/lib/libalpm/be_sync.c b/lib/libalpm/be_sync.c
index 5502d92d..ae46c120 100644
--- a/lib/libalpm/be_sync.c
+++ b/lib/libalpm/be_sync.c
@@ -136,6 +136,7 @@ valid:
 	return 0;
 }
 
+
 /** Update a package database
  *
  * An update of the package database \a db will be attempted. Unless
@@ -173,14 +174,15 @@ valid:
  */
 int SYMEXPORT alpm_db_update(int force, alpm_db_t *db)
 {
-	char *syncpath;
-	const char *dbext;
+	char *syncpath, *dbsig = NULL, *dbfilebak = NULL, *dbsigbak = NULL;
+	const char *dbext, *dbfile;
 	alpm_list_t *i;
 	int updated = 0;
 	int ret = -1;
 	mode_t oldmask;
 	alpm_handle_t *handle;
 	int siglevel;
+	size_t len;
 
 	/* Sanity checks */
 	ASSERT(db != NULL, return -1);
@@ -217,10 +219,39 @@ int SYMEXPORT alpm_db_update(int force, alpm_db_t *db)
 
 	dbext = handle->dbext;
 
+	/* create backup of current database version */
+	dbfile = _alpm_db_path(db);
+	len = strlen(dbfile) + 5;
+	MALLOC(dbfilebak, len,
+		{
+			handle->pm_errno = ALPM_ERR_MEMORY;
+			ret = -1;
+			goto cleanup;
+		}
+	);
+	snprintf(dbfilebak, len, "%s.bak", dbfile);
+
+
+	dbsig = _alpm_sigpath(db->handle, dbfile);
+	len = strlen(dbsig) + 5;
+	MALLOC(dbsigbak, len,
+		{
+			handle->pm_errno = ALPM_ERR_MEMORY;
+			ret = -1;
+			goto cleanup;
+		}
+	);
+	snprintf(dbsigbak, len, "%s.bak", dbsig);
+
+	/* remove any old backup files to prevent potential sig mismatch */
+	unlink(dbfilebak);
+	unlink(dbsigbak);
+	_alpm_copyfile(dbfile, dbfilebak);
+	_alpm_copyfile(dbsig, dbsigbak);
+
 	for(i = db->servers; i; i = i->next) {
 		const char *server = i->data, *final_db_url = NULL;
 		struct dload_payload payload;
-		size_t len;
 		int sig_ret = 0;
 
 		memset(&payload, 0, sizeof(struct dload_payload));
@@ -247,17 +278,6 @@ int SYMEXPORT alpm_db_update(int force, alpm_db_t *db)
 		updated = (updated || ret == 0);
 
 		if(ret != -1 && updated && (siglevel & ALPM_SIG_DATABASE)) {
-			/* an existing sig file is no good at this point */
-			char *sigpath = _alpm_sigpath(handle, _alpm_db_path(db));
-			if(!sigpath) {
-				/* pm_errno should be set */
-				ret = -1;
-				goto cleanup;
-			}
-			unlink(sigpath);
-			free(sigpath);
-
-
 			/* check if the final URL from internal downloader looks reasonable */
 			if(final_db_url != NULL) {
 				if(strlen(final_db_url) < 3
@@ -327,13 +347,23 @@ int SYMEXPORT alpm_db_update(int force, alpm_db_t *db)
 
 cleanup:
 	if(ret == -1) {
+		rename(dbfilebak, dbfile);
+		rename(dbsigbak, dbsig);
+
 		/* pm_errno was set by the download code */
 		_alpm_log(handle, ALPM_LOG_DEBUG, "failed to sync db: %s\n",
 				alpm_strerror(handle->pm_errno));
 	} else {
+		unlink(dbfilebak);
+		unlink(dbsigbak);
+
 		handle->pm_errno = ALPM_ERR_OK;
 	}
 
+	free(dbfilebak);
+	free(dbsig);
+	free(dbsigbak);
+
 	_alpm_handle_unlock(handle);
 	free(syncpath);
 	umask(oldmask);