2 files changed, 6 insertions, 0 deletions
diff --git a/src/lib/hash/md4/md4.cpp b/src/lib/hash/md4/md4.cpp
index 014ba8c2c..79f3a2d13 100644
--- a/src/lib/hash/md4/md4.cpp
+++ b/src/lib/hash/md4/md4.cpp
@@ -9,6 +9,11 @@
 
 namespace Botan {
 
+std::unique_ptr<HashFunction> MD4::copy_state() const
+   {
+   return std::unique_ptr<HashFunction>(new MD4(*this));
+   }
+
 namespace {
 
 /*
diff --git a/src/lib/hash/md4/md4.h b/src/lib/hash/md4/md4.h
index ebd0bdedd..c84cb0058 100644
--- a/src/lib/hash/md4/md4.h
+++ b/src/lib/hash/md4/md4.h
@@ -21,6 +21,7 @@ class BOTAN_DLL MD4 final : public MDx_HashFunction
       std::string name() const override { return "MD4"; }
       size_t output_length() const override { return 16; }
       HashFunction* clone() const override { return new MD4; }
+      std::unique_ptr<HashFunction> copy_state() const override;
 
       void clear() override;