diff -ru libgweather-3.4.0/configure.ac libgweather-3.4.0.patched/configure.ac
--- libgweather-3.4.0/configure.ac	2012-03-07 19:14:22.000000000 +0100
+++ libgweather-3.4.0.patched/configure.ac	2012-03-07 22:37:33.442156152 +0100
@@ -42,6 +42,7 @@
 
 LT_PREREQ([2.2.6])
 LT_INIT([dlopen win32-dll disable-static])
+LT_LIB_M
 
 IT_PROG_INTLTOOL([0.40.6])
 PKG_PROG_PKG_CONFIG([0.19])
diff -ru libgweather-3.4.0/libgweather/Makefile.am libgweather-3.4.0.patched/libgweather/Makefile.am
--- libgweather-3.4.0/libgweather/Makefile.am	2012-03-07 19:14:22.000000000 +0100
+++ libgweather-3.4.0.patched/libgweather/Makefile.am	2012-03-07 22:33:14.545255452 +0100
@@ -72,7 +72,7 @@
 
 test_sun_moon_SOURCES = test_sun_moon.c
 test_sun_moon_CPPFLAGS = $(AM_CPPFLAGS) $(LIBSOUP_CFLAGS)
-test_sun_moon_LDADD = libgweather-3.la $(GTK_LIBS)
+test_sun_moon_LDADD = libgweather-3.la $(GTK_LIBS) $(LIBM)
 
 gweather-enum-types.h: $(gweather_new_headers)
 	$(AM_V_GEN)( cd $(srcdir) && $(GLIB_MKENUMS) --template gweather-enum-types.h.tmpl \
