diff --git a/README.md b/README.md
index bad1704..fa01d6f 100644
--- a/README.md
+++ b/README.md
@@ -57,7 +57,6 @@ TODO
 - **documenation**: scope the readme audience to folks who kind of know what they're doing with servers
 - **documentation/feature**: use post-update rather than post-receive hook for simplicity
 - **documentation**: also describe use with post-commit hook
-- **feature**: need better detection and rendering of binary files
 - **feature**: multi-page or collapse-able files list
 - **feature**: commit log
 - **feature**: branches and releases (tags)
diff --git a/main.scm b/main.scm
index fd2b48b..b5cdc32 100755
--- a/main.scm
+++ b/main.scm
@@ -102,6 +102,13 @@ string-block
 (define (in-git-directory?)
   (not (eof-object? (call-with-input-pipe "git rev-parse --git-dir" read-line))))
 
+(define (is-text? path)
+  (not (equal?
+   "-\t-\t"
+   (call-with-input-pipe
+    (string-append "git diff 4b825dc642cb6eb9a060e54bf8d69288fbee4904 --numstat HEAD -- " path)
+    (lambda (port) (read-line port 4))))))
+
 (define (git-repository->paths-list)
   (call-with-input-pipe "git ls-tree -r --name-only HEAD" read-lines))
 
@@ -125,6 +132,8 @@ string-block
     (display "<pre>")
     (display-escaped-html (git-file->string source-file))
     (display "</pre>"))
+  (define (binary)
+   (display "<p>(Binary file)</p>"))
   (format #t "<p id=\"file-path\">~a</p>" source-file)
   (case (string->symbol (or source-extension source-filename))
     ;; markdown files get rendered in-place, unless there's an error, in which
@@ -143,9 +152,11 @@ string-block
     ((svg)
      (image-link) (plaintext))
     ((gz pack idx)
-     (display "<p>(Binary file)</p>"))
+     (binary))
     (else
-     (plaintext))))
+     (if (is-text? source-file)
+         (plaintext)
+         (binary)))))
 
 (define (display-files-html source-files-list)
   (display "<ul>\n")
@@ -155,9 +166,6 @@ string-block
    source-files-list)
   (display "</ul>\n"))
 
-(define (display-readme-html)
-  (markdown->html (git-file->string "README.md")))
-
 (define (display-contributors-html)
   (SXML->HTML
    `((h1 "Contributors")