--- Demo/CMakeLists.txt~	2010-01-19 14:50:25.000000000 -0600
+++ Demo/CMakeLists.txt	2010-07-15 08:41:34.182317902 -0500
@@ -17,7 +17,7 @@
 
 include_directories(${chipmunk_demos_include_dirs})
 add_executable(chipmunk_demos ${chipmunk_demos_source_files})
-target_link_libraries(chipmunk_demos ${chipmunk_demos_libraries})
+target_link_libraries(chipmunk_demos ${chipmunk_demos_libraries} -lm)
 
 if(INSTALL_DEMOS)
   install(TARGETS chipmunk_demos RUNTIME DESTINATION bin)