diff --git a/tools/chibi-ffi b/tools/chibi-ffi
index bb146df1..1733c3dd 100755
--- a/tools/chibi-ffi
+++ b/tools/chibi-ffi
@@ -1955,42 +1955,66 @@
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; main
 
-(let* ((args (command-line))
-       (args (if (pair? args) (cdr args) args))
-       (compile? (and (pair? args) (member (car args) '("-c" "--compile"))))
-       (args (if compile? (cdr args) args))
-       (cflags (if (and (pair? args) (member (car args) '("-f" "--flags")))
-                   (string-split (cadr args) #\space)
-                   #f))
-       (args (if cflags (cddr args) args))
-       (src (if (or (not (pair? args)) (equal? "-" (car args)))
-                "/dev/stdin"
-                (car args)))
-       (dest
-        (case (length args)
-          ((0) "-")
-          ((1) (string-append (strip-extension src) ".c"))
-          ((2) (cadr args))
-          (else (error "usage: chibi-ffi [-c] <file.stub> [<output.c>]")))))
-  (if (not (equal? "/dev/stdin" src))
-      (let ((slash (string-scan-right src #\/)))
-        (if (> slash 0)
-            (set! wdir (substring-cursor src 0 slash)))))
-  (if (equal? "-" dest)
-      (generate src)
-      (with-output-to-file dest (lambda () (generate src))))
-  (cond
-   ((and compile? (not (equal? "-" dest)))
-    ;; This has to use `eval' for bootstrapping, since we need
-    ;; chibi-ffi to compile to (chibi process) module.
-    (let* ((so (string-append (strip-extension src)
-                              *shared-object-extension*))
-           (execute (begin (eval '(import (chibi process)))
-                           (eval 'execute)))
-           (base-args (append (or cflags '())
-                              `("-o" ,so ,dest "-lchibi-scheme")))
-           (args (cond-expand
-                  (macosx (append '("-dynamiclib" "-Oz") base-args))
-                  (else (append '("-fPIC" "-shared" "-Os") base-args))))
-           (cc (if *c++?* "c++" "cc")))
-      (execute cc (cons cc args))))))
+(let ((args (command-line)))
+  (let lp ((args (if (pair? args) (cdr args) args))
+           (compile? #f)
+           (cflags '())
+           (features '()))
+    (cond
+     ((and (pair? args) (not (equal? "" (car args)))
+           (eqv? #\- (string-ref (car args) 0)))
+      (case (string->symbol (car args))
+        ((-c --compile)
+         (lp (cdr args) #t cflags features))
+        ((-f --flags)
+         (if (null? (cdr args))
+             (error "--flags requires an argument"))
+         (lp (cddr args)
+             compile?
+             (append cflag (string-split (cadr args) #\space))
+             features))
+        ((--features)
+         (if (null? (cdr args))
+             (error "--features requires an argument"))
+         (lp (cddr args)
+             compile?
+             cflags
+             (append features (string-split (cadr args) #\,))))
+        (else
+         (error "unknown option" (car args)))))
+     (else
+      (if (pair? features)
+          (set! *features* features))
+      (let* ((src (if (or (not (pair? args)) (equal? "-" (car args)))
+                      "/dev/stdin"
+                      (car args)))
+             (dest
+              (case (length args)
+                ((0) "-")
+                ((1) (string-append (strip-extension src) ".c"))
+                ((2) (cadr args))
+                (else
+                 (error "usage: chibi-ffi [-c] <file.stub> [<output.c>]")))))
+        (if (not (equal? "/dev/stdin" src))
+            (let ((slash (string-scan-right src #\/)))
+              (if (> slash 0)
+                  (set! wdir (substring-cursor src 0 slash)))))
+        (if (equal? "-" dest)
+            (generate src)
+            (with-output-to-file dest (lambda () (generate src))))
+        (cond
+         ((and compile? (not (equal? "-" dest)))
+          ;; This has to use `eval' for bootstrapping, since we need
+          ;; chibi-ffi to compile to (chibi process) module.
+          (let* ((so (string-append (strip-extension src)
+                                    *shared-object-extension*))
+                 (execute (begin (eval '(import (chibi process)))
+                                 (eval 'execute)))
+                 (base-args (append cflags `("-o" ,so ,dest "-lchibi-scheme")))
+                 (args
+                  (eval
+                   '(cond-expand
+                     (macosx (append '("-dynamiclib" "-Oz") base-args))
+                     (else (append '("-fPIC" "-shared" "-Os") base-args)))))
+                 (cc (if *c++?* "c++" "cc")))
+            (execute cc (cons cc args))))))))))
diff --git a/tools/chibi-genstatic b/tools/chibi-genstatic
index ae9a89ea..310e0444 100755
--- a/tools/chibi-genstatic
+++ b/tools/chibi-genstatic
@@ -358,23 +358,38 @@
   (display (init-name (cdr lib)))
   (display " },\n"))
 
-(let* ((args (command-line))
-       (_ (if (pair? args)
-              (set! wdir (path-directory (path-directory (car args))))))
-       (c-libs+c-files (find-c-libs (if (pair? args) (cdr args) args)))
-       (c-libs (car c-libs+c-files))
-       (c-files (cdr c-libs+c-files))
-       (inline? #t))
-  (newline)
-  (for-each (lambda (x) (include-c-lib x c-files inline?)) c-libs)
-  (newline)
-  ;; (display "typedef struct {\n")
-  ;; (display "  const char *name;\n")
-  ;; (display "  sexp_init_proc init;\n")
-  ;; (display "} sexp_library_entry_t;\n")
-  ;; (newline)
-  (display "struct sexp_library_entry_t sexp_static_libraries_array[] = {\n")
-  (for-each init-c-lib c-libs)
-  (display "  { NULL, NULL }\n")
-  (display "};\n\n")
-  (display "struct sexp_library_entry_t* sexp_static_libraries = sexp_static_libraries_array;\n"))
+(let ((args (command-line)))
+  (if (pair? args)
+      (set! wdir (path-directory (path-directory (car args)))))
+  (let lp ((args (if (pair? args) (cdr args) args))
+           (features '()))
+    (cond
+     ((and (pair? args) (not (equal? "" (car args)))
+           (eqv? #\- (string-ref (car args) 0)))
+      (case (string->symbol (car args))
+        ((--features)
+         (if (null? (cdr args))
+             (error "--features requires an argument"))
+         (lp (cddr args) (append features (string-split (cadr args) #\,))))
+        (else
+         (error "unknown option" (car args)))))
+     (else
+      (if (pair? features)
+          (set! *features* features))
+      (let* ((c-libs+c-files (find-c-libs (if (pair? args) (cdr args) args)))
+             (c-libs (car c-libs+c-files))
+             (c-files (cdr c-libs+c-files))
+             (inline? #t))
+        (newline)
+        (for-each (lambda (x) (include-c-lib x c-files inline?)) c-libs)
+        (newline)
+        ;; (display "typedef struct {\n")
+        ;; (display "  const char *name;\n")
+        ;; (display "  sexp_init_proc init;\n")
+        ;; (display "} sexp_library_entry_t;\n")
+        ;; (newline)
+        (display "struct sexp_library_entry_t sexp_static_libraries_array[] = {\n")
+        (for-each init-c-lib c-libs)
+        (display "  { NULL, NULL }\n")
+        (display "};\n\n")
+        (display "struct sexp_library_entry_t* sexp_static_libraries = sexp_static_libraries_array;\n"))))))