--- a/configure.in
+++ b/configure.in
@@ -7,6 +7,7 @@
 AC_PROG_MAKE_SET
 AC_PROG_CC
 AC_PROG_RANLIB
+AM_PROG_AR
 AC_PROG_INSTALL
 
 dnl Checks for libraries.
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1,8 +1,8 @@
 bin_PROGRAMS = mures
 
 mures_LDADD = \
-	-llua -L./lua
-	$(STATIC_LIBS)
+	-llua -L./lua \
+	$(STATIC_LIBS) -lm
 
 SUBDIRS = lua gui images maps sounds textures