diff --git a/ChangeLog b/ChangeLog
index 406fba643d..5fdf43010e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2008-07-22  Tor Lillqvist  <tml@novell.com>
+
+	* configure.in: Workaround for what apparently is a bug in MSYS:
+	returning -1 from main() is misinterpreted as exit status 0, so
+	make sure we return 0 or 1.
+
 2008-07-22  Sven Herzberg  <sven@imendio.com>
 
 	Add a test for my fixes from July 20th.
diff --git a/configure.in b/configure.in
index 2d1a6f9cbf..5a7d937ccf 100644
--- a/configure.in
+++ b/configure.in
@@ -1045,7 +1045,7 @@ main (int argc, char **argv)
 {
   char *content_type;
   content_type = g_content_type_guess (NULL, data, data_size, NULL);  
-  return strcmp (content_type, "image/png");
+  return !!strcmp (content_type, "image/png");
 }]])],
   [gio_can_sniff=yes
    AC_DEFINE(GDK_PIXBUF_USE_GIO_MIME, 1, [Define if gio can sniff image data])],