diff --git a/src/csync_journal.c b/src/csync_journal.c
index 23efc4f864..de27b1a6ee 100644
--- a/src/csync_journal.c
+++ b/src/csync_journal.c
@@ -35,16 +35,18 @@
 #define CSYNC_LOG_CATEGORY_NAME "csync.journal"
 #include "csync_log.h"
 
+#define BUF_SIZE 16
+
 static int csync_journal_check(const char *journal) {
   int fd = -1;
-  char buf[16] = {0};
+  char buf[BUF_SIZE] = {0};
   sqlite3 *db = NULL;
 
   /* check db version */
   fd = open(journal, O_RDONLY);
   if (fd >= 0) {
-    if (read(fd, (void *) buf, (size_t) 16) >= 0) {
-      buf[16] = '\0';
+    if (read(fd, (void *) buf, (size_t) BUF_SIZE - 1) >= 0) {
+      buf[BUF_SIZE] = '\0';
       close(fd);
       if (c_streq(buf, "SQLite format 3")) {
         if (sqlite3_open(journal, &db ) == SQLITE_OK) {