diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 8f36a7911b..7f74f4820c 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -579,7 +579,7 @@ gcc:centos8:amd64:
   variables:
     CC: gcc
     CFLAGS: "${CFLAGS_COMMON}"
-    EXTRA_CONFIGURE: "--with-libidn2"
+    EXTRA_CONFIGURE: "--enable-buffer-useinline --with-libidn2"
   <<: *centos_centos8_amd64_image
   <<: *build_job
 
diff --git a/lib/dns/rdata.c b/lib/dns/rdata.c
index 7a281c2ef7..7bdb6498de 100644
--- a/lib/dns/rdata.c
+++ b/lib/dns/rdata.c
@@ -1777,7 +1777,8 @@ inet_totext(int af, uint32_t flags, isc_region_t *src, isc_buffer_t *target) {
 			if (isc_buffer_availablelength(target) == 0) {
 				return (ISC_R_NOSPACE);
 			}
-			isc_buffer_putmem(target, "0", 1);
+			isc_buffer_putmem(target, (const unsigned char *)"0",
+					  1);
 		}
 	}
 
diff --git a/lib/isc/sockaddr.c b/lib/isc/sockaddr.c
index 8472739281..c01c3e65a3 100644
--- a/lib/isc/sockaddr.c
+++ b/lib/isc/sockaddr.c
@@ -144,7 +144,10 @@ isc_sockaddr_totext(const isc_sockaddr_t *sockaddr, isc_buffer_t *target) {
 			return (ISC_R_NOSPACE);
 		}
 
-		isc_buffer_putmem(target, sockaddr->type.sunix.sun_path, plen);
+		isc_buffer_putmem(
+			target,
+			(const unsigned char *)sockaddr->type.sunix.sun_path,
+			plen);
 
 		/*
 		 * Null terminate after used region.