diff --git a/verifier.cpp b/verifier.cpp
index 44098f7..22f1523 100644
--- a/verifier.cpp
+++ b/verifier.cpp
@@ -147,6 +147,12 @@
     LOG(INFO) << "comment is " << comment_size << " bytes; signature is " << signature_start
               << " bytes from end";
 
+    if (signature_start > comment_size) {
+        LOGE("signature start: %zu is larger than comment size: %zu\n", signature_start,
+             comment_size);
+        return VERIFY_FAILURE;
+    }
+
     if (signature_start <= FOOTER_SIZE) {
         LOG(ERROR) << "Signature start is in the footer";
         return VERIFY_FAILURE;