diff --git a/src/ckdb.c b/src/ckdb.c
index 6838b0f9..609e9afd 100644
--- a/src/ckdb.c
+++ b/src/ckdb.c
@@ -2993,7 +2993,7 @@ static void summarise_blocks()
 	double diffacc, diffinv, shareacc, shareinv;
 	tv_t now, elapsed_start, elapsed_finish;
 	int64_t elapsed, wi_start, wi_finish;
-	BLOCKS *blocks, *prev_blocks;
+	BLOCKS *blocks = NULL, *prev_blocks;
 	WORKINFO *prev_workinfo;
 	SHARESUMMARY looksharesummary, *sharesummary;
 	WORKMARKERS lookworkmarkers, *workmarkers;
diff --git a/src/ckdb.h b/src/ckdb.h
index f658044d..3c8b4ac1 100644
--- a/src/ckdb.h
+++ b/src/ckdb.h
@@ -55,7 +55,7 @@
 
 #define DB_VLOCK "1"
 #define DB_VERSION "1.0.4"
-#define CKDB_VERSION DB_VERSION"-1.600"
+#define CKDB_VERSION DB_VERSION"-1.601"
 
 #define WHERE_FFL " - from %s %s() line %d"
 #define WHERE_FFL_HERE __FILE__, __func__, __LINE__
diff --git a/src/ckdb_data.c b/src/ckdb_data.c
index ac1aaabe..0cbde05d 100644
--- a/src/ckdb_data.c
+++ b/src/ckdb_data.c
@@ -4618,7 +4618,7 @@ static bool gen_workmarkers(PGconn *conn, MARKS *stt, bool after, MARKS *fin,
 {
 	K_ITEM look, *wi_stt_item, *wi_fin_item, *old_wm_item;
 	WORKMARKERS *old_wm;
-	WORKINFO workinfo, *wi_stt, *wi_fin;
+	WORKINFO workinfo, *wi_stt = NULL, *wi_fin;
 	K_TREE_CTX ctx[1];
 	char description[TXT_BIG+1];
 	bool ok;
@@ -4731,7 +4731,7 @@ bool workmarkers_generate(PGconn *conn, char *err, size_t siz, char *by,
 			  bool none_error)
 {
 	K_ITEM *m_item, *m_next_item;
-	MARKS *mused, *mnext;
+	MARKS *mused = NULL, *mnext;
 	MARKS marks;
 	K_TREE_CTX ctx[1];
 	K_ITEM look;