thodg/libgit2

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6f2a2bb..d6b3275 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -17,6 +17,8 @@ CMAKE_MINIMUM_REQUIRED(VERSION 2.6)
 # Add find modules to the path
 SET(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_CURRENT_LIST_DIR}/cmake/Modules/")
 
+INCLUDE(CheckLibraryExists)
+
 # Build options
 #
 OPTION( SONAME				"Set the (SO)VERSION of the target"		ON  )
@@ -78,7 +80,9 @@ FUNCTION(TARGET_OS_LIBRARIES target)
 	ELSEIF(CMAKE_SYSTEM_NAME MATCHES "(Solaris|SunOS)")
 		TARGET_LINK_LIBRARIES(${target} socket nsl)
 		SET(LIBGIT2_PC_LIBS "${LIBGIT2_PC_LIBS} -lsocket -lnsl" PARENT_SCOPE)
-	ELSEIF(CMAKE_SYSTEM_NAME MATCHES "Linux")
+	ENDIF()
+	CHECK_LIBRARY_EXISTS(rt clock_gettime "time.h" NEED_LIBRT)
+	IF(NEED_LIBRT)
 		TARGET_LINK_LIBRARIES(${target} rt)
 		SET(LIBGIT2_PC_LIBS "${LIBGIT2_PC_LIBS} -lrt" PARENT_SCOPE)
 	ENDIF()