diff --git a/docs/CREDITS.txt b/docs/CREDITS.txt
index f7da37f..c88c50b 100644
--- a/docs/CREDITS.txt
+++ b/docs/CREDITS.txt
@@ -164,6 +164,9 @@ CMake fixes:
 Bug fixes,
     Rémi Verschelde
 
+Bug fixes:
+    Rob Loach
+
 Other stuff:
     Your name here! Patches go to icculus@icculus.org ...
 
diff --git a/extras/physfsrwops.c b/extras/physfsrwops.c
index 8e5857c..a8654ab 100644
--- a/extras/physfsrwops.c
+++ b/extras/physfsrwops.c
@@ -32,10 +32,16 @@
 #endif
 
 #if !TARGET_SDL2
+#ifndef RW_SEEK_SET
 #define RW_SEEK_SET SEEK_SET
+#endif
+#ifndef RW_SEEK_CUR
 #define RW_SEEK_CUR SEEK_CUR
+#endif
+#ifndef RW_SEEK_END
 #define RW_SEEK_END SEEK_END
 #endif
+#endif
 
 #if TARGET_SDL2
 static Sint64 SDLCALL physfsrwops_size(struct SDL_RWops *rw)