diff --git a/CHANGES b/CHANGES
index 7b04c15e2b..0b9cb91e47 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,5 @@
+3900.	[bug]		Fix a crash in PostgreSQL DLZ driver. [RT #36637]
+
 3899.	[bug]		"request-ixfr" is only applicable to slave and redirect
 			zones. [RT #36608]
 
diff --git a/contrib/dlz/drivers/dlz_postgres_driver.c b/contrib/dlz/drivers/dlz_postgres_driver.c
index 8254e0487d..85ba5761e3 100644
--- a/contrib/dlz/drivers/dlz_postgres_driver.c
+++ b/contrib/dlz/drivers/dlz_postgres_driver.c
@@ -577,6 +577,7 @@ postgres_get_resultset(const char *zone, const char *record,
 #endif
 			PQclear(*rs);	/* get rid of it */
 			/* in case this was the last attempt */
+			*rs = NULL;
 			result = ISC_R_FAILURE;
 		}
 	}