diff --git a/src/p_wcle.cpp b/src/p_wcle.cpp
index dbce4d77..f059d623 100644
--- a/src/p_wcle.cpp
+++ b/src/p_wcle.cpp
@@ -778,6 +778,8 @@ int PackWcle::canUnpack()
     // FIXME: 1024 could be too large for some files
     //int len = 1024;
     int len = UPX_MIN(getImageSize(), 256u);
+    if (len == 0)
+        return false;
     return readPackHeader(len) ? 1 : -1;
 }