diff --git a/src/lib/knx/knx.h b/src/lib/knx/knx.h
index 981cc642..ea376fde 100644
--- a/src/lib/knx/knx.h
+++ b/src/lib/knx/knx.h
@@ -22,6 +22,12 @@
 #include <string>
 #include <cstdint>
 
+#if defined(__GNUC__)
+#define MAYBE_UNUSED __attribute__((unused))
+#else
+#define MAYBE_UNUSED
+#endif
+
 namespace ebusd {
 
 /** @file lib/knx/knx.h
@@ -160,7 +166,7 @@ class KnxConnection {
   /**
    * @param address the individual address to set.
    */
-  virtual void setAddress(knx_addr_t address) {
+  virtual void setAddress(MAYBE_UNUSED knx_addr_t address) {
     // default implementation does nothing
   }
 
@@ -176,7 +182,7 @@ class KnxConnection {
    * Set the programming mode.
    * @param on true to start programming mode, false to stop it.
    */
-  virtual void setProgrammingMode(bool on) {
+  virtual void setProgrammingMode(MAYBE_UNUSED bool on) {
     // default implementation does nothing
   }
 };
diff --git a/src/lib/utils/httpclient.cpp b/src/lib/utils/httpclient.cpp
index 8a369c93..48b9f661 100755
--- a/src/lib/utils/httpclient.cpp
+++ b/src/lib/utils/httpclient.cpp
@@ -28,6 +28,12 @@
 #endif  // HAVE_SSL
 #include "lib/utils/log.h"
 
+#if defined(__GNUC__)
+#define MAYBE_UNUSED __attribute__((unused))
+#else
+#define MAYBE_UNUSED
+#endif
+
 namespace ebusd {
 
 using std::string;
@@ -171,7 +177,7 @@ void sslInfoCallback(const SSL *ssl, int type, int val) {
     (type & SSL_CB_ALERT) ? SSL_alert_desc_string_long(val) : "?");
 }
 
-int bioInfoCallback(BIO *bio, int state, int res) {
+int bioInfoCallback(MAYBE_UNUSED BIO *bio, int state, int res) {
   logDebug(lf_network,
     "SSL BIO state %d res %d",
     state,