diff --git a/src/os/macosx/macos.h b/src/os/macosx/macos.h
--- a/src/os/macosx/macos.h
+++ b/src/os/macosx/macos.h
@@ -75,14 +75,4 @@ static inline bool MacOSVersionIsAtLeast
 	return true;
 }
 
-/*
- * OSX 10.3.9 has blessed us with a signal with unlikable side effects.
- * The most problematic side effect is that it makes OpenTTD 'think' that
- * it's running on 10.4.0 or higher and thus tries to link to functions
- * that are only defined there. So now we'll remove all and any signal
- * handling for OSX < 10.4 and 10.3.9 works as it should at the cost of
- * not giving a useful error when savegame loading goes wrong.
- */
-#define signal(sig, func) (MacOSVersionIsAtLeast(10, 4, 0) ? signal(sig, func) : NULL)
-
 #endif /* MACOS_H */
diff --git a/src/os/unix/unix.cpp b/src/os/unix/unix.cpp
--- a/src/os/unix/unix.cpp
+++ b/src/os/unix/unix.cpp
@@ -21,7 +21,9 @@
 #include <time.h>
 #include <signal.h>
 
-#if (defined(_POSIX_VERSION) && _POSIX_VERSION >= 200112L) || defined(__GLIBC__)
+#ifdef __APPLE__
+	#include <sys/mount.h>
+#elif (defined(_POSIX_VERSION) && _POSIX_VERSION >= 200112L) || defined(__GLIBC__)
 	#define HAS_STATVFS
 #endif
 
@@ -71,17 +73,16 @@ bool FiosGetDiskFreeSpace(const char *pa
 {
 	uint64 free = 0;
 
-#ifdef HAS_STATVFS
-# ifdef __APPLE__
-	/* OSX 10.3 lacks statvfs so don't try to use it even though later versions of OSX has it. */
-	if (MacOSVersionIsAtLeast(10, 4, 0))
-# endif
-	{
-		struct statvfs s;
+#ifdef __APPLE__
+	struct statfs s;
 
-		if (statvfs(path, &s) != 0) return false;
-		free = (uint64)s.f_frsize * s.f_bavail;
-	}
+	if (statfs(path, &s) != 0) return false;
+	free = (uint64)s.f_bsize * s.f_bavail;
+#elif defined(HAS_STATVFS)
+	struct statvfs s;
+
+	if (statvfs(path, &s) != 0) return false;
+	free = (uint64)s.f_frsize * s.f_bavail;
 #endif
 	if (tot != NULL) *tot = free;
 	return true;