diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2d90ade3..89b25f9d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -403,7 +403,7 @@ install_module(toxcore DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/tox)
 # endif()
 # 
 # if(MSGPACK_FOUND)
-#   add_c_executable(toxcore-sut
+#   add_binary(toxcore-sut
 #     testing/hstox/binary_decode.c
 #     testing/hstox/binary_encode.c
 #     testing/hstox/driver.c
@@ -445,7 +445,7 @@ endif()
 
 function(auto_test target)
   if(CHECK_FOUND AND NOT ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC" AND ARGV1 STREQUAL "MSVC_DONT_BUILD"))
-    add_c_executable(auto_${target}_test auto_tests/${target}_test.c)
+    add_binary(auto_${target}_test auto_tests/${target}_test.c)
     target_link_modules(auto_${target}_test
       toxcore
       toxcrypto
@@ -460,8 +460,8 @@ function(auto_test target)
 endfunction()
 
 if(BUILD_TOXAV)
-  add_c_executable(auto_monolith_test
-    auto_tests/monolith_test.c
+  add_binary(auto_monolith_test
+    auto_tests/monolith_test.cpp
     ${ANDROID_CPU_FEATURES})
   target_link_modules(auto_monolith_test
     ${LIBSODIUM_LIBRARIES}
@@ -511,7 +511,7 @@ endif()
 
 option(DHT_BOOTSTRAP "Enable building of DHT_bootstrap" ON)
 if(DHT_BOOTSTRAP)
-  add_c_executable(DHT_bootstrap
+  add_binary(DHT_bootstrap
     other/DHT_bootstrap.c
     other/bootstrap_node_packets.c)
   target_link_modules(DHT_bootstrap toxnetcrypto)
@@ -523,7 +523,7 @@ if(BOOTSTRAP_DAEMON)
     message(FATAL_ERROR "Building tox-bootstrapd for Windows is not supported")
   endif()
   if(LIBCONFIG_FOUND)
-    add_c_executable(tox-bootstrapd
+    add_binary(tox-bootstrapd
       other/bootstrap_daemon/src/command_line_arguments.c
       other/bootstrap_daemon/src/command_line_arguments.h
       other/bootstrap_daemon/src/config.c
@@ -554,7 +554,7 @@ option(BUILD_AV_TEST "Build toxav test" ON)
 if(NOT WIN32
   AND BUILD_AV_TEST AND BUILD_TOXAV
   AND SNDFILE_FOUND AND PORTAUDIO_FOUND AND OPENCV_FOUND)
-  add_c_executable(av_test testing/av_test.c)
+  add_binary(av_test testing/av_test.c)
   target_link_modules(av_test
     toxcore
     ${OPENCV_LIBRARIES}
@@ -567,23 +567,23 @@ if(NOT WIN32
   endif()
 endif()
 
-add_c_executable(DHT_test testing/DHT_test.c)
+add_binary(DHT_test testing/DHT_test.c)
 target_link_modules(DHT_test toxdht)
 
-add_c_executable(Messenger_test testing/Messenger_test.c)
+add_binary(Messenger_test testing/Messenger_test.c)
 target_link_modules(Messenger_test toxmessenger)
 
 if(NOT WIN32)
-  add_c_executable(tox_sync testing/tox_sync.c)
+  add_binary(tox_sync testing/tox_sync.c)
   target_link_modules(tox_sync toxcore)
 endif()
 
 if(UTIL_LIBRARIES)
-  add_c_executable(tox_shell testing/tox_shell.c)
+  add_binary(tox_shell testing/tox_shell.c)
   target_link_modules(tox_shell toxcore ${UTIL_LIBRARIES})
 endif()
 
 if(NOT WIN32)
-  add_c_executable(irc_syncbot testing/irc_syncbot.c)
+  add_binary(irc_syncbot testing/irc_syncbot.c)
   target_link_modules(irc_syncbot toxcore toxnetwork)
 endif()
diff --git a/auto_tests/BUILD b/auto_tests/BUILD
index f4542ccb..8e218b51 100644
--- a/auto_tests/BUILD
+++ b/auto_tests/BUILD
@@ -15,6 +15,7 @@ cc_library(
     srcs = [src],
     copts = [
         "-Wno-parentheses",
+        "-Wno-sign-compare",
     ],
     deps = [
         ":helpers",
@@ -25,4 +26,4 @@ cc_library(
         "//c-toxcore/toxencryptsave",
         "@check",
     ],
-) for src in glob(["*_test.c"])]
+) for src in glob(["*_test.c*"])]
diff --git a/auto_tests/monolith_test.c b/auto_tests/monolith_test.cpp
similarity index 100%
rename from auto_tests/monolith_test.c
rename to auto_tests/monolith_test.cpp
diff --git a/cmake/ModulePackage.cmake b/cmake/ModulePackage.cmake
index 35f6f2a7..8867fc45 100644
--- a/cmake/ModulePackage.cmake
+++ b/cmake/ModulePackage.cmake
@@ -28,7 +28,7 @@ macro(set_source_language)
   endif()
 endmacro()
 
-function(add_c_executable exec)
+function(add_binary exec)
   set_source_language(${ARGN})
 
   add_executable(${exec} ${ARGN})
diff --git a/toxcore/network.c b/toxcore/network.c
index fb4748d4..7d6e415a 100644
--- a/toxcore/network.c
+++ b/toxcore/network.c
@@ -26,7 +26,9 @@
 #endif
 
 #define _DARWIN_C_SOURCE
+#ifndef _XOPEN_SOURCE
 #define _XOPEN_SOURCE 600
+#endif
 
 #if defined(_WIN32) && _WIN32_WINNT >= _WIN32_WINNT_WINXP
 #define _WIN32_WINNT  0x501
diff --git a/toxcore/util.c b/toxcore/util.c
index 92bbb68c..85584f09 100644
--- a/toxcore/util.c
+++ b/toxcore/util.c
@@ -27,7 +27,9 @@
 #include "config.h"
 #endif
 
+#ifndef _XOPEN_SOURCE
 #define _XOPEN_SOURCE 600
+#endif
 
 #include "util.h"