diff --git a/bsdiffpatch-test.c b/bsdiffpatch-test.c
new file mode 100644
index 0000000..043bc15
--- /dev/null
+++ b/bsdiffpatch-test.c
@@ -0,0 +1,130 @@
+/*-
+ * Copyright 2015 Colin Walters <walters@verbum.org>
+ * All rights reserved
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted providing that the following conditions 
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/* Compile with $(pkg-config --cflags --libs glib-2.0) */
+
+#include "bsdiff.h"
+#undef BSDIFF_EXECUTABLE
+#include "bsdiff.c"
+#include "bspatch.c"
+
+#include <glib.h>
+#include <err.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdio.h>
+
+static int
+bsdiff_write_gstring (struct bsdiff_stream *stream,
+		      const void *buf,
+		      int size)
+{
+  g_string_append_len ((GString*)stream->opaque, buf, size);
+  return 0;
+}
+
+typedef struct {
+  GString *buf;
+  size_t off;
+} GStringInputStream;
+
+static int
+gstringin_read (const struct bspatch_stream* stream, void* buffer, int length)
+{
+  GStringInputStream *gin = stream->opaque;
+  size_t rlen = MIN(gin->buf->len - gin->off, length);
+
+  if (rlen == 0)
+    return 0;
+
+  memcpy (buffer, gin->buf->str + gin->off, rlen);
+  gin->off += rlen;
+
+  return 0;
+}
+
+int main(int argc,char *argv[])
+{
+  const char *original = NULL;
+  size_t original_len;
+  const char *modified = NULL;
+  size_t modified_len;
+  GString *gmembuf = g_string_new (NULL);
+  GString *gpatchbuf = g_string_new (NULL);
+
+  {
+    ssize_t bytes_read;
+    char inbuf[1024];
+    while ((bytes_read = read (0, inbuf, sizeof (inbuf))) != 0)
+    g_string_append_len (gmembuf, inbuf, bytes_read);
+    if (bytes_read < 0)
+      err (1, "read");
+    if (gmembuf->len < 2)
+      errx (1, "Input length is less than 2");
+  }
+
+  original = gmembuf->str;
+  original_len = gmembuf->len / 2;
+  modified = original + original_len;
+  modified_len = gmembuf->len - original_len;
+  g_string_free (gmembuf, FALSE);
+  gmembuf = NULL;
+
+  {
+    struct bsdiff_stream stream;
+    
+    stream.malloc = malloc;
+    stream.free = free;
+    stream.write = bsdiff_write_gstring;
+    stream.opaque = gpatchbuf;
+    if (bsdiff (original, original_len, modified, modified_len, &stream))
+      err(1, "bsdiff");
+  }
+
+  {
+    GStringInputStream gin = { gpatchbuf, 0 };
+    struct bspatch_stream pstream;
+    GString *newbuf = g_string_new (NULL);
+
+    pstream.opaque = &gin;
+    pstream.read = gstringin_read;
+
+    g_string_set_size (newbuf, modified_len);
+    
+    if (bspatch (original, original_len, newbuf->str, modified_len, &pstream))
+      errx (1, "bspatch failed");
+
+    if (memcmp (modified, newbuf->str, modified_len) != 0)
+      errx (1, "bspatch did not reproduce modified content!");
+
+    g_string_free (newbuf, TRUE);
+  }
+
+  /* Free the memory we used */
+  g_string_free (gpatchbuf, TRUE);
+
+  return 0;
+}