diff --git a/src/cairo-image-info.c b/src/cairo-image-info.c
index f84bcaf04..8fc770550 100644
--- a/src/cairo-image-info.c
+++ b/src/cairo-image-info.c
@@ -179,7 +179,7 @@ _jpx_get_box_contents (const unsigned char *p)
 static cairo_bool_t
 _jpx_match_box (const unsigned char *p, const unsigned char *end, uint32_t type)
 {
-    uint length;
+    uint32_t length;
 
     if (p + 8 < end) {
 	length = _get_be32 (p);