--- yajl-2.0.4-orig/CMakeLists.txt
+++ yajl-2.0.4-libm/CMakeLists.txt
@@ -60,6 +60,7 @@ ELSE (WIN32)
 
   SET(CMAKE_C_FLAGS_DEBUG "-DDEBUG -g")
   SET(CMAKE_C_FLAGS_RELEASE "-DNDEBUG -O2 -Wuninitialized")
+  SET(CMAKE_SHARED_LINKER_FLAGS "-lm ${CMAKE_SHARED_LINKER_FLAGS}")
 ENDIF (WIN32)