diff -r a666e4eefd27 QTfrontend/CMakeLists.txt
--- a/QTfrontend/CMakeLists.txt	Wed Jan 08 23:49:08 2014 +0100
+++ b/QTfrontend/CMakeLists.txt	Thu Jan 09 17:32:26 2014 +0100
@@ -216,7 +216,7 @@
 endif()

 if(CMAKE_CXX_COMPILER MATCHES "clang*")
-    list(APPEND HW_LINK_LIBS stdc++)
+    list(APPEND HW_LINK_LIBS stdc++ m)
 endif()

 target_link_libraries(hedgewars ${HW_LINK_LIBS})
diff -r a666e4eefd27 project_files/hwc/rtl/CMakeLists.txt
--- a/project_files/hwc/rtl/CMakeLists.txt	Wed Jan 08 23:49:08 2014 +0100
+++ b/project_files/hwc/rtl/CMakeLists.txt	Thu Jan 09 17:32:26 2014 +0100
@@ -4,6 +4,7 @@
 file(GLOB fpcrtl_src *.c)

 add_library(fpcrtl STATIC ${fpcrtl_src})
+target_link_libraries(fpcrtl m)

 #if(WEBGL)
 #    set_target_properties(fpcrtl PROPERTIES PREFIX "em")