diff --git a/stepmania/src/archutils/Darwin/arch_setup.h b/stepmania/src/archutils/Darwin/arch_setup.h
index 3390322c03..adbbd2ff81 100644
--- a/stepmania/src/archutils/Darwin/arch_setup.h
+++ b/stepmania/src/archutils/Darwin/arch_setup.h
@@ -12,6 +12,7 @@ typedef unsigned long long UInt64;
 #define NEED_COSF
 #define NEED_TANF
 #define NEED_ACOSF
+#define NEED_STRTOF
 #define BACKTRACE_LOOKUP_METHOD_DARWIN_DYLD
 #define BACKTRACE_METHOD_POWERPC_DARWIN
 #define HAVE_VERSION_INFO