--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -110,7 +110,7 @@
 
 
 
-rubrica2_LDADD = $(top_builddir)/libral/libral.la $(RUBRICA_LIBS) $(LIBRAL_LIBS)
+rubrica2_LDADD = $(top_builddir)/libral/libral.la $(RUBRICA_LIBS) $(LIBRAL_LIBS) $(LIBM)
 
 
 
--- a/configure.in
+++ b/configure.in
@@ -102,6 +102,10 @@
 AC_DEFINE_UNQUOTED(RUBRICA_CAP_NAME, "$RUBRICA_CAP_NAME", The program name with capital initial letter)
 AC_DEFINE_UNQUOTED(RUBRICA_VERSION, "$RUBRICA_VERSION", The program version)
 
+dnl
+dnl libm
+LT_LIB_M
+dnl
 
 dnl
 dnl Start of pkg-config checks