diff --git a/src/backend/commands/dbcommands.c b/src/backend/commands/dbcommands.c
index 95881a8550..01d66212e9 100644
--- a/src/backend/commands/dbcommands.c
+++ b/src/backend/commands/dbcommands.c
@@ -26,6 +26,7 @@
 #include "access/genam.h"
 #include "access/heapam.h"
 #include "access/htup_details.h"
+#include "access/multixact.h"
 #include "access/tableam.h"
 #include "access/xact.h"
 #include "access/xloginsert.h"
@@ -103,14 +104,14 @@ createdb(ParseState *pstate, const CreatedbStmt *stmt)
 	Relation	rel;
 	Oid			src_dboid;
 	Oid			src_owner;
-	int			src_encoding;
-	char	   *src_collate;
-	char	   *src_ctype;
+	int			src_encoding = -1;
+	char	   *src_collate = NULL;
+	char	   *src_ctype = NULL;
 	bool		src_istemplate;
 	bool		src_allowconn;
-	Oid			src_lastsysoid;
-	TransactionId src_frozenxid;
-	MultiXactId src_minmxid;
+	Oid			src_lastsysoid = InvalidOid;
+	TransactionId src_frozenxid = InvalidTransactionId;
+	MultiXactId src_minmxid = InvalidMultiXactId;
 	Oid			src_deftablespace;
 	volatile Oid dst_deftablespace;
 	Relation	pg_database_rel;