diff --git a/thin-provisioning/metadata_checker.cc b/thin-provisioning/metadata_checker.cc
index c4572d4..1d064a7 100644
--- a/thin-provisioning/metadata_checker.cc
+++ b/thin-provisioning/metadata_checker.cc
@@ -46,6 +46,12 @@ super_block_corruption::visit(metadata_damage_visitor &visitor) const
 	visitor.visit(*this);
 }
 
+bool
+super_block_corruption::operator ==(super_block_corruption const &rhs) const
+{
+	return true;
+}
+
 //--------------------------------
 
 missing_device_details::missing_device_details(range64 missing)
@@ -59,6 +65,12 @@ missing_device_details::visit(metadata_damage_visitor &visitor) const
 	visitor.visit(*this);
 }
 
+bool
+missing_device_details::operator ==(missing_device_details const &rhs) const
+{
+	return missing_ == rhs.missing_;
+}
+
 //--------------------------------
 
 missing_devices::missing_devices(range64 missing)
@@ -72,6 +84,12 @@ missing_devices::visit(metadata_damage_visitor &visitor) const
 	visitor.visit(*this);
 }
 
+bool
+missing_devices::operator ==(missing_devices const &rhs) const
+{
+	return missing_ == rhs.missing_;
+}
+
 //--------------------------------
 
 missing_mappings::missing_mappings(uint64_t dev, range64 missing)
@@ -86,6 +104,12 @@ missing_mappings::visit(metadata_damage_visitor &visitor) const
 	visitor.visit(*this);
 }
 
+bool
+missing_mappings::operator ==(missing_mappings const &rhs) const
+{
+	return dev_ == rhs.dev_ && missing_ == rhs.missing_;
+}
+
 //--------------------------------
 
 bad_metadata_ref_count::bad_metadata_ref_count(block_address b,
@@ -103,6 +127,12 @@ bad_metadata_ref_count::visit(metadata_damage_visitor &visitor) const
 	visitor.visit(*this);
 }
 
+bool
+bad_metadata_ref_count::operator ==(bad_metadata_ref_count const &rhs) const
+{
+	return b_ == rhs.b_ && actual_ == rhs.actual_ && expected_ == rhs.expected_;
+}
+
 //--------------------------------
 
 bad_data_ref_count::bad_data_ref_count(block_address b,
@@ -120,6 +150,12 @@ bad_data_ref_count::visit(metadata_damage_visitor &visitor) const
 	visitor.visit(*this);
 }
 
+bool
+bad_data_ref_count::operator ==(bad_data_ref_count const &rhs) const
+{
+	return b_ == rhs.b_ && actual_ == rhs.actual_ && expected_ == rhs.expected_;
+}
+
 //--------------------------------
 
 missing_metadata_ref_counts::missing_metadata_ref_counts(range64 missing)
@@ -133,6 +169,12 @@ missing_metadata_ref_counts::visit(metadata_damage_visitor &visitor) const
 	visitor.visit(*this);
 }
 
+bool
+missing_metadata_ref_counts::operator ==(missing_metadata_ref_counts const &rhs) const
+{
+	return missing_ == rhs.missing_;
+}
+
 //--------------------------------
 
 missing_data_ref_counts::missing_data_ref_counts(range64 missing)
@@ -146,6 +188,12 @@ missing_data_ref_counts::visit(metadata_damage_visitor &visitor) const
 	visitor.visit(*this);
 }
 
+bool
+missing_data_ref_counts::operator ==(missing_data_ref_counts const &rhs) const
+{
+	return missing_ == rhs.missing_;
+}
+
 //--------------------------------
 
 void
diff --git a/thin-provisioning/metadata_checker.h b/thin-provisioning/metadata_checker.h
index d024138..4db98b8 100644
--- a/thin-provisioning/metadata_checker.h
+++ b/thin-provisioning/metadata_checker.h
@@ -53,6 +53,7 @@ namespace thin_provisioning {
 
 	class super_block_corruption : public metadata_damage {
 		void visit(metadata_damage_visitor &visitor) const;
+		bool operator ==(super_block_corruption const &rhs) const;
 	};
 
 	typedef range<uint64_t> range64;
@@ -60,6 +61,7 @@ namespace thin_provisioning {
 	struct missing_device_details : public metadata_damage {
 		missing_device_details(range64 missing);
 		virtual void visit(metadata_damage_visitor &visitor) const;
+		bool operator ==(missing_device_details const &rhs) const;
 
 		range64 missing_;
 	};
@@ -67,6 +69,7 @@ namespace thin_provisioning {
 	struct missing_devices : public metadata_damage {
 		missing_devices(range64 missing);
 		virtual void visit(metadata_damage_visitor &visitor) const;
+		bool operator ==(missing_devices const &rhs) const;
 
 		range64 missing_;
 	};
@@ -74,6 +77,7 @@ namespace thin_provisioning {
 	struct missing_mappings : public metadata_damage {
 		missing_mappings(uint64_t dev, range64 missing);
 		virtual void visit(metadata_damage_visitor &visitor) const;
+		bool operator ==(missing_mappings const &rhs) const;
 
 		uint64_t dev_;
 		range64 missing_;
@@ -85,6 +89,7 @@ namespace thin_provisioning {
 				       ref_t expected);
 
 		virtual void visit(metadata_damage_visitor &visitor) const;
+		bool operator ==(bad_metadata_ref_count const &rhs) const;
 
 		block_address b_;
 		ref_t actual_;
@@ -97,6 +102,7 @@ namespace thin_provisioning {
 				   ref_t expected);
 
 		virtual void visit(metadata_damage_visitor &visitor) const;
+		bool operator ==(bad_data_ref_count const &rhs) const;
 
 		block_address b_;
 		ref_t actual_;
@@ -106,6 +112,7 @@ namespace thin_provisioning {
 	struct missing_metadata_ref_counts : public metadata_damage {
 		missing_metadata_ref_counts(range64 missing);
 		virtual void visit(metadata_damage_visitor &visitor) const;
+		bool operator ==(missing_metadata_ref_counts const &rhs) const;
 
 		range64 missing_;
 	};
@@ -113,6 +120,7 @@ namespace thin_provisioning {
 	struct missing_data_ref_counts : public metadata_damage {
 		missing_data_ref_counts(range64 missing);
 		virtual void visit(metadata_damage_visitor &visitor) const;
+		bool operator ==(missing_data_ref_counts const &rhs) const;
 
 		range64 missing_;
 	};