diff --git a/CMakeLists.txt b/CMakeLists.txt
index e91ed5507..9da4ca9a8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -312,18 +312,15 @@ if (MSVC)
 
 #$(SolutionDir)<toolset>msvc,<variant>release:<linkflags>/OPT:ICF=5
 #$(SolutionDir)<toolset>msvc,<variant>release:<linkflags>/OPT:REF
-else()
+elseif ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
 	add_definitions(-Wno-c++11-extensions)
+	add_definitions(-fcolor-diagnostics)
 endif()
 
 add_definitions(-D_FILE_OFFSET_BITS=64)
 add_definitions(-DBOOST_EXCEPTION_DISABLE)
 add_definitions(-DBOOST_ASIO_ENABLE_CANCELIO)
 
-if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
-	add_definitions(-fcolor-diagnostics)
-endif()
-
 if (tcmalloc)
 	target_link_libraries(torrent-rasterbar tcmalloc)
 endif()
diff --git a/src/alert.cpp b/src/alert.cpp
index a047ee45c..9b6b725dd 100644
--- a/src/alert.cpp
+++ b/src/alert.cpp
@@ -1807,7 +1807,7 @@ namespace libtorrent {
 		char ih_hex[41];
 		to_hex((const char*)&info_hash[0], 20, ih_hex);
 		char msg[200];
-		snprintf(msg, sizeof(msg), "incoming dht get_peers reply: %s, peers %ld", ih_hex, m_num_peers);
+		snprintf(msg, sizeof(msg), "incoming dht get_peers reply: %s, peers %d", ih_hex, m_num_peers);
 		return msg;
 	}
 
diff --git a/src/asio_ssl.cpp b/src/asio_ssl.cpp
index f762048e3..cea812335 100644
--- a/src/asio_ssl.cpp
+++ b/src/asio_ssl.cpp
@@ -13,6 +13,7 @@
 // only define BOOST_ASIO_DECL if it hasn't already been defined
 // or if it has been defined to an empty string
 #if TORRENT_HAS_ASIO_DECL == x
+#undef BOOST_ASIO_DECL
 #define BOOST_ASIO_DECL BOOST_SYMBOL_EXPORT
 #endif
 
diff --git a/src/file.cpp b/src/file.cpp
index d09e46612..513f86569 100644
--- a/src/file.cpp
+++ b/src/file.cpp
@@ -278,7 +278,10 @@ done:
 	}
 }
 # else
-#  define _BSD_SOURCE
+#  undef _BSD_SOURCE
+#  define _BSD_SOURCE // deprecated since glibc 2.20
+#  undef _DEFAULT_SOURCE
+#  define _DEFAULT_SOURCE
 #  include <sys/uio.h>
 # endif
 #endif