diff --git a/Makefile b/Makefile
index e1e8b215..fb8145c0 100644
--- a/Makefile
+++ b/Makefile
@@ -86,9 +86,9 @@ sexp-ulimit.o: sexp.c $(BASE_INCLUDES)
 main.o: main.c $(INCLUDES)
 	$(CC) -c $(XCPPFLAGS) $(XCFLAGS) -o $@ $<
 
-SEXP_OBJS = gc.o sexp.o opt/bignum.o
-SEXP_ULIMIT_OBJS = gc.o sexp-ulimit.o opt/bignum.o
-EVAL_OBJS = opcodes.o vm.o eval.o opt/simplify.o
+SEXP_OBJS = gc.o sexp.o bignum.o
+SEXP_ULIMIT_OBJS = gc.o sexp-ulimit.o bignum.o
+EVAL_OBJS = opcodes.o vm.o eval.o simplify.o
 
 libchibi-sexp$(SO): $(SEXP_OBJS)
 	$(CC) $(CLIBFLAGS) -o $@ $^ $(XLDFLAGS)
diff --git a/opt/bignum.c b/bignum.c
similarity index 100%
rename from opt/bignum.c
rename to bignum.c
diff --git a/eval.c b/eval.c
index 1bf2d333..62bf6348 100644
--- a/eval.c
+++ b/eval.c
@@ -1583,10 +1583,6 @@ sexp sexp_make_promise (sexp ctx, sexp self, sexp_sint_t n, sexp done, sexp val)
 }
 #endif
 
-#ifdef PLAN9
-#include "opt/plan9.c"
-#endif
-
 /***************************** opcodes ********************************/
 
 #if SEXP_USE_TYPE_DEFS
diff --git a/include/chibi/eval.h b/include/chibi/eval.h
index 03236f03..9c0c6da1 100644
--- a/include/chibi/eval.h
+++ b/include/chibi/eval.h
@@ -193,6 +193,34 @@ SEXP_API sexp sexp_make_setter_op (sexp ctx, sexp self, sexp_sint_t n, sexp name
 SEXP_API sexp sexp_type_slot_offset_op (sexp ctx, sexp self, sexp_sint_t n, sexp type, sexp index);
 #endif
 
+#ifdef PLAN9
+SEXP_API sexp sexp_rand (sexp ctx, sexp self, sexp_sint_t n);
+SEXP_API sexp sexp_srand (sexp ctx, sexp self, sexp_sint_t n, sexp seed);
+SEXP_API sexp sexp_file_exists_p (sexp ctx, sexp self, sexp_sint_t n, sexp path);
+SEXP_API sexp sexp_fdopen (sexp ctx, sexp self, sexp_sint_t n, sexp fd, sexp mode);
+SEXP_API sexp sexp_fileno (sexp ctx, sexp self, sexp_sint_t n, sexp port);
+SEXP_API sexp sexp_fork (sexp ctx, sexp self, sexp_sint_t n);
+SEXP_API sexp sexp_exec (sexp ctx, sexp self, sexp_sint_t n, sexp name, sexp args);
+SEXP_API void sexp_exits (sexp ctx, sexp self, sexp_sint_t n, sexp msg);
+SEXP_API sexp sexp_dup (sexp ctx, sexp self, sexp_sint_t n, sexp oldfd, sexp newfd);
+SEXP_API sexp sexp_pipe (sexp ctx, sexp self, sexp_sint_t n);
+SEXP_API sexp sexp_sleep (sexp ctx, sexp self, sexp_sint_t n, sexp msecs);
+SEXP_API sexp sexp_getenv (sexp ctx, sexp self, sexp_sint_t n, sexp name);
+SEXP_API sexp sexp_getwd (sexp ctx, sexp self, sexp_sint_t n);
+SEXP_API sexp sexp_chdir (sexp ctx, sexp self, sexp_sint_t n, sexp path);
+SEXP_API sexp sexp_getuser (sexp ctx, sexp self, sexp_sint_t n);
+SEXP_API sexp sexp_sysname (sexp ctx, sexp self, sexp_sint_t n);
+SEXP_API sexp sexp_wait (sexp ctx, sexp self, sexp_sint_t n);
+SEXP_API sexp sexp_postnote (sexp ctx, sexp self, sexp_sint_t n, sexp pid, sexp note);
+SEXP_API sexp sexp_postmountsrv (sexp ctx, sexp self, sexp_sint_t n, sexp ls, sexp name, sexp mtpt, sexp flags);
+SEXP_API sexp sexp_9p_req_offset (sexp ctx, sexp self, sexp_sint_t n, sexp req);
+SEXP_API sexp sexp_9p_req_count (sexp ctx, sexp self, sexp_sint_t n, sexp req);
+SEXP_API sexp sexp_9p_req_fid (sexp ctx, sexp self, sexp_sint_t n, sexp req);
+SEXP_API sexp sexp_9p_req_newfid (sexp ctx, sexp self, sexp_sint_t n, sexp req);
+SEXP_API sexp sexp_9p_respond (sexp ctx, sexp self, sexp_sint_t n, sexp req, sexp err);
+SEXP_API sexp sexp_9p_responderror (sexp ctx, sexp self, sexp_sint_t n, sexp req);
+#endif
+
 #if SEXP_USE_SIMPLIFY
 SEXP_API int sexp_rest_unused_p (sexp lambda);
 #else
diff --git a/include/chibi/sexp.h b/include/chibi/sexp.h
index 5c20fa76..87513549 100755
--- a/include/chibi/sexp.h
+++ b/include/chibi/sexp.h
@@ -25,8 +25,10 @@ extern "C" {
 #if SEXP_USE_DL
 #include <dlfcn.h>
 #endif
+#ifndef PLAN9
 #include <errno.h>
 #include <unistd.h>
+#endif
 #if SEXP_USE_GREEN_THREADS
 #include <sys/time.h>
 #include <fcntl.h>
diff --git a/mkfile b/mkfile
index 0cabf51c..791f949b 100644
--- a/mkfile
+++ b/mkfile
@@ -11,7 +11,7 @@ CPPFLAGS= -Iinclude -DPLAN9 -DSEXP_USE_GREEN_THREADS=0
 CFLAGS= -p $CPPFLAGS
 CFLAGS_STATIC=$CFLAGS -DSEXP_USE_STATIC_LIBS
 
-OFILES=sexp.$O eval.$O main.$O $STATIC
+OFILES=gc.$O sexp.$O bignum.$O opcodes.$O plan9.$O vm.$O simplify.$O eval.$O main.$O $STATIC
 HFILES=include/chibi/sexp.h include/chibi/eval.h include/chibi/features.h include/chibi/install.h
 CLEANFILES=tests/basic/*.out tests/basic/*.err
 
@@ -107,5 +107,3 @@ test-unicode:
 
 test-libs:
 	./$O.out -xscheme tests/lib-tests.scm
-
-sexp.c:N:	gc.c opt/bignum.c
diff --git a/opt/plan9.c b/plan9.c
similarity index 99%
rename from opt/plan9.c
rename to plan9.c
index 23ff33ce..5022acad 100644
--- a/opt/plan9.c
+++ b/plan9.c
@@ -1,7 +1,9 @@
 /*  plan9.c -- extended Plan 9 system utils                   */
-/*  Copyright (c) 2009-2010 Alex Shinn.  All rights reserved. */
+/*  Copyright (c) 2009-2012 Alex Shinn.  All rights reserved. */
 /*  BSD-style license: http://synthcode.com/license.txt       */
 
+#include "chibi/eval.h"
+
 sexp sexp_rand (sexp ctx, sexp self, sexp_sint_t n) {
   return sexp_make_fixnum(rand());
 }
diff --git a/opt/simplify.c b/simplify.c
similarity index 100%
rename from opt/simplify.c
rename to simplify.c