diff --git a/src/event/ngx_event_openssl.c b/src/event/ngx_event_openssl.c
index 1b39f33c2..39f7cae89 100644
--- a/src/event/ngx_event_openssl.c
+++ b/src/event/ngx_event_openssl.c
@@ -4069,7 +4069,7 @@ ngx_ssl_parse_time(
 
     BIO_write(bio, "Tue ", sizeof("Tue ") - 1);
     ASN1_TIME_print(bio, asn1time);
-    len = BIO_get_mem_data(bio, &value);
+    len = BIO_get_mem_data(bio, (char **) &value);
 
     time = ngx_parse_http_time(value, len);
 
diff --git a/src/event/ngx_event_openssl_stapling.c b/src/event/ngx_event_openssl_stapling.c
index 2100516f9..5e1eb502d 100644
--- a/src/event/ngx_event_openssl_stapling.c
+++ b/src/event/ngx_event_openssl_stapling.c
@@ -793,7 +793,7 @@ ngx_ssl_stapling_time(ASN1_GENERALIZEDTIME *asn1time)
 
     BIO_write(bio, "Tue ", sizeof("Tue ") - 1);
     ASN1_GENERALIZEDTIME_print(bio, asn1time);
-    len = BIO_get_mem_data(bio, &value);
+    len = BIO_get_mem_data(bio, (char **) &value);
 
     time = ngx_parse_http_time(value, len);