--- a/configure.ac
+++ b/configure.ac
@@ -80,6 +80,8 @@
 		AM_CONDITIONAL(WITH_ZINNIA,[false])		
 ])
 
+AC_CHECK_LIB([m],[atan2])
+
 # check ibus
 PKG_CHECK_MODULES(IBUS, [
     ibus-1.0 >= 1.3