diff --git a/rtengine/canon_cr3_decoder.cc b/rtengine/canon_cr3_decoder.cc
index f9850189c..51beb66f3 100644
--- a/rtengine/canon_cr3_decoder.cc
+++ b/rtengine/canon_cr3_decoder.cc
@@ -602,7 +602,9 @@ int DCraw::parseCR3(
                             relpos_inBox += lTag;
                         }
                     }
-
+                    if (!szItem) {
+                        goto fin;
+                    }
                     relpos_inDir += szItem;
                 }