diff --git a/src/script/sign.h b/src/script/sign.h
index 7ade715ee..245b15410 100644
--- a/src/script/sign.h
+++ b/src/script/sign.h
@@ -188,6 +188,9 @@ template<typename Stream>
 void SerializeHDKeypaths(Stream& s, const std::map<CPubKey, std::vector<uint32_t>>& hd_keypaths, uint8_t type)
 {
     for (auto keypath_pair : hd_keypaths) {
+        if (!keypath_pair.first.IsValid()) {
+            throw std::ios_base::failure("Invalid CPubKey being serialized");
+        }
         SerializeToVector(s, type, MakeSpan(keypath_pair.first));
         WriteCompactSize(s, keypath_pair.second.size() * sizeof(uint32_t));
         for (auto& path : keypath_pair.second) {