diff --git a/stepmania/configure.ac b/stepmania/configure.ac
index 863d431a68..1ffe284193 100644
--- a/stepmania/configure.ac
+++ b/stepmania/configure.ac
@@ -20,10 +20,28 @@ AC_SEARCH_LIBS(mad_synth_init, [mad], have_mad=yes,  have_mad=no)
 AC_PROG_CC
 AC_PROG_CXX
 
-AC_CHECK_FUNCS(powf sqrtf sinf cosf acosf)
-
 AM_PATH_SDL
 
+# We could do this more cleanly with an AC_CHECK_FUNCS wrapper.
+AC_CHECK_FUNCS([powf sqrtf sinf cosf acosf])
+AH_VERBATIM([VA_ZZZ_NEEDED_FUNCS],
+[#if !defined(HAVE_POWF)
+#define NEED_POWF
+#endif
+#if !defined(HAVE_SQRTF)
+#define NEED_SQRTF
+#endif
+#if !defined(HAVE_SINF)
+#define NEED_SINF
+#endif
+#if !defined(HAVE_COSF)
+#define NEED_COSF
+#endif
+#if !defined(HAVE_ACOSF)
+#define NEED_ACOSF
+#endif
+])
+
 # sdl-config puts -L/usr/lib in the library search path, which reorders things
 # in a way that breaks some configurations.
 SDL_LIBS="`echo $SDL_LIBS | sed 's_-L/usr/lib/\?[[ $]]__'`"