diff --git a/src/coap_notls.c b/src/coap_notls.c
index 621ab0f4..64dd9f04 100644
--- a/src/coap_notls.c
+++ b/src/coap_notls.c
@@ -165,8 +165,13 @@ ssize_t coap_tls_read(coap_session_t *session UNUSED,
 
 #else /* !HAVE_LIBTINYDTLS && !HAVE_OPENSSL */
 
-/* make compilers happy that do not like empty modules */
+/* Make compilers happy that do not like empty modules. As this
+ * function is never used, we ignore -Wunused-function temporarily.
+ */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunused-function"
 static inline void dummy(void) {
 }
+#pragma GCC diagnostic pop
 
 #endif /* !HAVE_LIBTINYDTLS && !HAVE_OPENSSL */
diff --git a/src/coap_openssl.c b/src/coap_openssl.c
index 58db28f3..2a20ecdb 100644
--- a/src/coap_openssl.c
+++ b/src/coap_openssl.c
@@ -1174,8 +1174,13 @@ ssize_t coap_tls_read(coap_session_t *session,
 
 #else /* !HAVE_OPENSSL */
 
-/* make compilers happy that do not like empty modules */
+/* Make compilers happy that do not like empty modules. As this
+ * function is never used, we ignore -Wunused-function temporarily.
+ */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunused-function"
 static inline void dummy(void) {
 }
+#pragma GCC diagnostic pop
 
 #endif /* HAVE_OPENSSL */
diff --git a/src/coap_tinydtls.c b/src/coap_tinydtls.c
index f718c0a4..3a5e6493 100644
--- a/src/coap_tinydtls.c
+++ b/src/coap_tinydtls.c
@@ -503,8 +503,13 @@ ssize_t coap_tls_read(coap_session_t *session UNUSED,
 
 #else /* !HAVE_LIBTINYDTLS */
 
- /* make compilers happy that do not like empty modules */
+/* Make compilers happy that do not like empty modules. As this
+ * function is never used, we ignore -Wunused-function temporarily.
+ */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunused-function"
 static inline void dummy(void) {
 }
+#pragma GCC diagnostic pop
 
 #endif /* HAVE_LIBTINYDTLS */