diff --git a/d1x-rebirth/include/ignorecase.h b/common/include/ignorecase.h
similarity index 100%
rename from d1x-rebirth/include/ignorecase.h
rename to common/include/ignorecase.h
diff --git a/d2x-rebirth/include/ignorecase.h b/d2x-rebirth/include/ignorecase.h
deleted file mode 100644
index 873202e09..000000000
--- a/d2x-rebirth/include/ignorecase.h
+++ /dev/null
@@ -1,75 +0,0 @@
-/** \file ignorecase.h */
-
-/**
- * \mainpage PhysicsFS ignorecase
- *
- * This is an extension to PhysicsFS to let you handle files in a
- *  case-insensitive manner, regardless of what sort of filesystem or
- *  archive they reside in. It does this by enumerating directories as
- *  needed and manually locating matching entries.
- *
- * Please note that this brings with it some caveats:
- *  - On filesystems that are case-insensitive to start with, such as those
- *    used on Windows or MacOS, you are adding extra overhead.
- *  - On filesystems that are case-sensitive, you might select the wrong dir
- *    or file (which brings security considerations and potential bugs). This
- *    code favours exact case matches, but you will lose access to otherwise
- *    duplicate filenames, or you might go down a wrong directory tree, etc.
- *    In practive, this is rarely a problem, but you need to be aware of it.
- *  - This doesn't do _anything_ with the write directory; you're on your
- *    own for opening the right files for writing. You can sort of get around
- *    this by adding your write directory to the search path, but then the
- *    interpolated directory tree can screw you up even more.
- *
- * This code should be considered an aid for legacy code. New development
- *  shouldn't do dumbass things that require this aid in the first place.  :)
- *
- * Usage: Set up PhysicsFS as you normally would, then use
- *  PHYSFSEXT_locateCorrectCase() to get a "correct" pathname to pass to
- *  functions like PHYSFS_openRead(), etc.
- *
- * License: this code is public domain. I make no warranty that it is useful,
- *  correct, harmless, or environmentally safe.
- *
- * This particular file may be used however you like, including copying it
- *  verbatim into a closed-source project, exploiting it commercially, and
- *  removing any trace of my name from the source (although I hope you won't
- *  do that). I welcome enhancements and corrections to this file, but I do
- *  not require you to send me patches if you make changes. This code has
- *  NO WARRANTY.
- *
- * Unless otherwise stated, the rest of PhysicsFS falls under the zlib license.
- *  Please see LICENSE in the root of the source tree.
- *
- *  \author Ryan C. Gordon.
- */
-
-
-/**
- * \fn int PHYSFSEXT_locateCorrectCase(char *buf)
- * \brief Find an existing filename with matching case.
- *
- * This function will look for a path/filename that matches the passed in
- *  buffer. Each element of the buffer's path is checked for a
- *  case-insensitive match. The buffer must specify a null-terminated string
- *  in platform-independent notation.
- *
- * Please note results may be skewed differently depending on whether symlinks
- *  are enabled or not.
- *
- * Each element of the buffer is overwritten with the actual case of an
- *  existing match. If there is no match, the search aborts and reports an
- *  error. Exact matches are favored over case-insensitive matches.
- *
- * THIS IS RISKY. Please do not use this function for anything but crappy
- *  legacy code.
- *
- *   \param buf Buffer with null-terminated string of path/file to locate.
- *               This buffer will be modified by this function.
- *  \return zero if match was found, -1 if the final element (the file itself)
- *               is missing, -2 if one of the parent directories is missing.
- */
-int PHYSFSEXT_locateCorrectCase(char *buf);
-
-/* end of ignorecase.h ... */
-