diff --git a/lib/chibi/reload.scm b/lib/chibi/reload.scm
new file mode 100644
index 00000000..b43bf0d4
--- /dev/null
+++ b/lib/chibi/reload.scm
@@ -0,0 +1,63 @@
+
+(define last-modified-time (current-seconds))
+
+(define reload-verbose? (make-parameter #f))
+
+(define (warn msg . args)
+  (let ((err (current-error-port)))
+    (display msg err)
+    (display ":" err)
+    (for-each (lambda (a)
+                (display " " err)
+                (if (string? a) (display a err) (write a err)))
+              args)
+    (newline err)))
+
+(define (reload module-name)
+  (if (reload-verbose?)
+      (warn "Reloading module" module-name))
+  (let ((old-module (find-module module-name)))
+    ;; Remove old entry in modules list.
+    (delete-module! module-name)
+    (guard (exn (else (warn "Error loading module definition" module-name)
+                      (print-exception exn)
+                      (print-stack-trace)
+                      (add-module! module-name old-module)))
+      (load-module-definition module-name)
+      (let ((module (find-module module-name)))
+        (cond
+         ((not module) (warn "Couldn't find module" module-name))
+         (else
+          (guard (exn (else (warn "Error loading module" module-name)
+                            (print-exception exn)
+                            (print-stack-trace)
+                            (delete-module! module-name)
+                            (add-module! module-name old-module)))
+            (let ((env (eval-module module-name module)))
+              (%import (module-env module) env (module-exports module) #f)
+              ))))))))
+
+(define (file-modified? path)
+  (and path (> (file-modification-time path) last-modified-time)))
+
+(define (module-definition-modified? module-name module)
+  (file-modified? (find-module-file (module-name->file module-name))))
+
+(define (module-includes-modified? module)
+  (any
+   (lambda (x)
+     (and (pair? x) (memq (car x) '(include include-ci))
+          (any file-modified? (map find-module-file (cdr x)))))
+   (module-meta-data module)))
+
+(define (module-modified? module-name module)
+  (or (module-definition-modified? module-name module)
+      (module-includes-modified? module)))
+
+(define (reload-modified-modules)
+  (for-each
+   (lambda (x)
+     (if (module-modified? (car x) (cdr x))
+         (reload (car x))))
+   *modules*)
+  (set! last-modified-time (current-seconds)))
diff --git a/lib/chibi/reload.sld b/lib/chibi/reload.sld
new file mode 100644
index 00000000..edff64db
--- /dev/null
+++ b/lib/chibi/reload.sld
@@ -0,0 +1,9 @@
+
+(define-library (chibi reload)
+  (import (scheme)
+          (meta)
+          (srfi 39)
+          (only (chibi time) current-seconds)
+          (only (chibi filesystem) file-modification-time))
+  (include "reload.scm")
+  (export reload reload-modified-modules reload-verbose?))