diff --git a/daemon/src/sip/sip_utils.h b/daemon/src/sip/sip_utils.h
index 2e70cf5aa2c06d9ee4abcead65c093fa16b054e7..e64fbba8889f5266a3d0691ffce4650175c87d1e 100644
--- a/daemon/src/sip/sip_utils.h
+++ b/daemon/src/sip/sip_utils.h
@@ -42,6 +42,7 @@
 #include <utility>
 #include <string>
 #include <vector>
+#include <cstring> // strcmp
 
 struct pjsip_msg;
 
@@ -56,8 +57,9 @@ constexpr const char* getKeyExchangeName(KeyExchangeProtocol kx) {
     return kx == KeyExchangeProtocol::SDES ? "sdes" : (
         kx == KeyExchangeProtocol::ZRTP ? "zrtp" : "");
 }
-constexpr KeyExchangeProtocol getKeyExchangeProtocol(const char* name) {
-    return !strcmp("sdes", name) ? KeyExchangeProtocol::SDES : KeyExchangeProtocol::NONE;
+
+static inline KeyExchangeProtocol getKeyExchangeProtocol(const char* name) {
+    return !std::strcmp("sdes", name) ? KeyExchangeProtocol::SDES : KeyExchangeProtocol::NONE;
 }
 
 /**