diff --git a/extras/buildbot-os2.sh b/extras/buildbot-os2.sh
new file mode 100755
index 0000000..7a96824
--- /dev/null
+++ b/extras/buildbot-os2.sh
@@ -0,0 +1,70 @@
+#!/bin/bash
+
+# This is used by the buildbot to cross-compile for OS/2 from Linux, using
+#  OpenWatcom. In an ideal world, we wouldn't need this, but we need a few
+#  things to do this "properly" ...
+#
+#  - OS/2 running as a VMware guest on the build machine
+#  - Buildbot-worker running on that OS/2 guest
+#  - CMake for OS/2 that...
+#  -  ... has Open Watcom compiler support and...
+#  -  ... a Watcom WMake project generator.
+#
+# Some of these things are doable (there is a CMake port for OS/2, you can
+#  use GCC with it), but since OpenWatcom will just target OS/2 on Linux just
+#  like it could on OS/2, it's easier and more efficient to just have a
+#  buildbot script compile it here.
+#
+# Note that we just blast all the C files through the wcc386 compiler and
+#  skip CMake entirely. We should fix this at some point.
+
+set -e
+
+export WATCOM="/usr/local/share/watcom"
+export PATH="$PATH:$WATCOM/binl"
+
+CFLAGS="-i=\"$WATCOM/h;$WATCOM/h/os2;../src\" -wx -zq -bt=os2 -fo=.obj -mf"
+WLIBFLAGS="-b -c -n -q -p=512"
+
+cd `dirname "$0"`
+cd ..
+mkdir -p buildbot
+cd buildbot
+
+rm -f test_physfs.obj
+
+OKAY="1"
+for src in ../src/*.c ; do
+    echo wcc386 $src $CFLAGS
+    wcc386 $src $CFLAGS || OKAY="0"
+done
+
+if [ "$OKAY" == "1" ]; then
+    echo wlib $WLIBFLAGS physfs.lib *.obj
+    wlib $WLIBFLAGS physfs.lib *.obj || OKAY="0"
+fi
+
+echo wcc386 ../test/test_physfs.c $CFLAGS
+wcc386 ../test/test_physfs.c $CFLAGS || OKAY="0"
+
+if [ "$OKAY" == "1" ]; then
+    LDFLAGS="name test_physfs d all sys os2v2 op m libr physfs op q op symf FIL test_physfs.obj"
+    echo wlink $LDFLAGS
+    wlink $LDFLAGS || OKAY="0"
+fi
+
+if [ "$OKAY" == "1" ]; then
+    F=`file ../buildbot/test_physfs.exe`
+    echo "$F"
+    if [ "$F" != '../buildbot/test_physfs.exe: MS-DOS executable, LX for OS/2 (console) i80386' ]; then
+        echo 1>&2 "ERROR: final binary doesn't appear to be OS/2 executable."
+        OKAY=0
+    fi
+fi
+
+if [ "$OKAY" == "1" ]; then
+    echo 1>&2 "Build succeeded."
+else
+    echo 1>&2 "Build failed."
+fi
+