diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5da7472927b44fa818ef74a6007f3d3dae7fda00..08c248f32a122deb25b86534ed038e460e269500 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -36,6 +36,7 @@ list (APPEND dhtnet_SOURCES
     src/peer_connection.cpp
     src/string_utils.cpp
     src/fileutils.cpp
+    src/ip_utils.cpp
     src/security/tls_session.cpp
     src/security/certstore.cpp
     src/security/threadloop.cpp
@@ -46,7 +47,7 @@ list (APPEND dhtnet_SOURCES
     src/upnp/protocol/mapping.cpp
     src/upnp/upnp_context.cpp
     src/upnp/upnp_control.cpp
-    src/upnp/protocol/igd.cpp   
+    src/upnp/protocol/igd.cpp
 )
 
 list (APPEND dhtnet_HEADERS
diff --git a/src/ip_utils.cpp b/src/ip_utils.cpp
index e3fd748418e3d0e9cd71ce8534b365a7160499ca..8bda17425f007bed8c87643ff8c19bb2ec7fa0d9 100644
--- a/src/ip_utils.cpp
+++ b/src/ip_utils.cpp
@@ -15,9 +15,10 @@
  *  along with this program. If not, see <https://www.gnu.org/licenses/>.
  */
 #include "ip_utils.h"
-#include "logger.h"
+#include "sip_utils.h"
+#include "string_utils.h"
 
-#include "connectivity/sip_utils.h"
+#include <fmt/format.h>
 
 #include <sys/types.h>
 #include <unistd.h>
@@ -52,7 +53,7 @@ std::string_view
 sip_strerror(pj_status_t code)
 {
     thread_local char err_msg[PJ_ERR_MSG_SIZE];
-    return as_view(pj_strerror(code, err_msg, sizeof err_msg));
+    return sip_utils::as_view(pj_strerror(code, err_msg, sizeof err_msg));
 }
 
 
@@ -185,7 +186,7 @@ ip_utils::getGateway(char* localHost, ip_utils::subnet_mask prefix)
     std::vector<std::string_view> tokens = split_string(localHostStr, '.');
     // Build a gateway address from the individual ip components.
     for (unsigned i = 0; i <= (unsigned) prefix; i++)
-        defaultGw += tokens[i] + ".";
+        defaultGw = fmt::format("{:s}{:s}.", defaultGw, tokens[i]);
     for (unsigned i = (unsigned) ip_utils::subnet_mask::prefix_32bit;
          i > (unsigned) prefix + 1;
          i--)