--- a/configure.ac
+++ b/configure.ac
@@ -44,6 +44,7 @@
 AM_PROG_CC_C_O
 AC_PROG_CPP
 AC_PROG_AWK
+AM_PROG_AR
 AC_PROG_RANLIB
 AC_PROG_LN_S
 
@@ -112,7 +113,7 @@
 # Checks for typedefs, structures, and compiler characteristics.
 # ==============================================================
 
-AM_C_PROTOTYPES
+AC_C_PROTOTYPES
 AC_C_CONST
 AC_TYPE_UID_T     dnl This checks for gid_t too.
 AC_CHECK_TYPES([ssize_t])
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -42,7 +42,7 @@
 heroeslvl_SOURCES = heroeslvl.c
 
 heroes_LDADD = lvl/libhlvl.a media/libhmcommon.a ../lib/libheroes.a \
-	       $(INTLLIBS) $(LIBALT_LOCAL_XLDADD) $(LIBALT_XLDADD)
+	       $(INTLLIBS) $(LIBALT_LOCAL_XLDADD) $(LIBALT_XLDADD) -lm
 heroes_LDFLAGS = $(LIBALT_XLDFLAGS)
 
 ## Depend upon Makefile because the value of LIBALT_LOCAL_LDADD might