diff --git a/meson.build b/meson.build
index 3a8b724..30f23d6 100644
--- a/meson.build
+++ b/meson.build
@@ -48,7 +48,6 @@ c_args = '''
         -Wwrite-strings
         -Wno-unused-parameter
         -Wno-missing-field-initializers
-        -Wno-unused-result
         -Werror=overflow
         -Werror=sign-compare
         -Wdate-time
diff --git a/src/netlog/netlog-dtls.c b/src/netlog/netlog-dtls.c
index ff89e58..eac5deb 100644
--- a/src/netlog/netlog-dtls.c
+++ b/src/netlog/netlog-dtls.c
@@ -148,10 +148,10 @@ int dtls_connect(DTLSManager *m, SocketAddress *address) {
                 if (cert) {
                         _cleanup_(OPENSSL_freep) void *subject = NULL, *issuer = NULL;
 
-                        subject = X509_NAME_oneline(X509_get_subject_name(cert), 0, 0);
+                        subject = X509_NAME_oneline(X509_get_subject_name(cert), NULL, 0);
                         log_debug("DTLS: Subject: %s", (char *) subject);
 
-                        issuer = X509_NAME_oneline(X509_get_issuer_name(cert), 0, 0);
+                        issuer = X509_NAME_oneline(X509_get_issuer_name(cert), NULL, 0);
                         log_debug("DTLS: Issuer: %s", (char *) issuer);
                 } else
                         log_debug("DTLS: No certificates.");
diff --git a/src/netlog/netlog-ssl.c b/src/netlog/netlog-ssl.c
index d0c4450..3718525 100644
--- a/src/netlog/netlog-ssl.c
+++ b/src/netlog/netlog-ssl.c
@@ -9,7 +9,7 @@
 #include "netlog-dtls.h"
 #include "netlog-tls.h"
 
-static_assert(offsetof(TLSManager, auth_mode) == offsetof(DTLSManager, auth_mode));
+static_assert(offsetof(TLSManager, auth_mode) == offsetof(DTLSManager, auth_mode), "TLSManager and DTLSManager must be similar");
 
 /* inspired by SSL_set_verify(3) */
 int ssl_verify_certificate_validity(int preverify_ok, X509_STORE_CTX *store) {
diff --git a/src/netlog/netlog-tls.c b/src/netlog/netlog-tls.c
index 1f72b0c..218baaa 100644
--- a/src/netlog/netlog-tls.c
+++ b/src/netlog/netlog-tls.c
@@ -147,10 +147,10 @@ int tls_connect(TLSManager *m, SocketAddress *address) {
                 if (cert) {
                         _cleanup_(OPENSSL_freep) void *subject = NULL, *issuer = NULL;
 
-                        subject = X509_NAME_oneline(X509_get_subject_name(cert), 0, 0);
+                        subject = X509_NAME_oneline(X509_get_subject_name(cert), NULL, 0);
                         log_debug("TLS: SSL Subject: %s", (char *) subject);
 
-                        issuer = X509_NAME_oneline(X509_get_issuer_name(cert), 0, 0);
+                        issuer = X509_NAME_oneline(X509_get_issuer_name(cert), NULL, 0);
                         log_debug("TLS: SSL Issuer: %s", (char *) issuer);
                 } else
                         log_debug("TLS: SSL No certificates.");
diff --git a/src/share/hexdecoct.c b/src/share/hexdecoct.c
index 6338533..6f3ec85 100644
--- a/src/share/hexdecoct.c
+++ b/src/share/hexdecoct.c
@@ -35,6 +35,7 @@ int undecchar(char c) {
 }
 
 char hexchar(int x) {
+        __attribute__ ((nonstring))
         static const char table[16] = "0123456789abcdef";
 
         return table[x & 15];