diff --git a/src/storage.cr b/src/storage.cr
index 4885e38..fee984b 100644
--- a/src/storage.cr
+++ b/src/storage.cr
@@ -164,9 +164,11 @@ class DNSManager::Storage
 
 		domain = @domains_by_name.get domain_name
 		if domain.share_key.nil?
-			domain.share_key = UUID.random.to_s
-			@domains_by_name.update_or_create domain_name, domain
-			Response::DomainChanged.new domain
+			# Clone the domain so the database doesn't try to remove the new `shared_key`.
+			domain_cloned = domain.clone
+			domain_cloned.share_key = UUID.random.to_s
+			@domains_by_name.update domain_name, domain_cloned
+			Response::DomainChanged.new domain_cloned
 		else
 			Response::Error.new "The domain already have a share key."
 		end
@@ -177,9 +179,11 @@ class DNSManager::Storage
 
 		domain = @domains_by_name.get domain_name
 		if domain.transfer_key.nil?
-			domain.transfer_key = UUID.random.to_s
-			@domains_by_name.update_or_create domain_name, domain
-			Response::DomainChanged.new domain
+			# Clone the domain so the database doesn't try to remove the new `transfer_key`.
+			domain_cloned = domain.clone
+			domain_cloned.transfer_key = UUID.random.to_s
+			@domains_by_name.update domain_name, domain_cloned
+			Response::DomainChanged.new domain_cloned
 		else
 			Response::Error.new "The domain already have a transfer key."
 		end
@@ -192,9 +196,11 @@ class DNSManager::Storage
 
 		domain = @domains_by_name.get domain_name
 		if domain.owners.size == 1 && domain.owners[0] == user_id
-			domain.share_key = nil
-			@domains_by_name.update domain
-			Response::DomainChanged.new domain
+			# Clone the domain so the old `shared_key` still exists in the old version.
+			domain_cloned = domain.clone
+			domain_cloned.share_key = nil
+			@domains_by_name.update domain_cloned
+			Response::DomainChanged.new domain_cloned
 		else
 			Response::Error.new "You are not the only owner."
 		end
@@ -205,17 +211,20 @@ class DNSManager::Storage
 			if domain.owners.includes? user_id
 				return Response::Error.new "You already own this domain."
 			end
-			domain.owners << user_id
-			@domains_by_name.update domain
-			Response::DomainChanged.new domain
+			domain_cloned = domain.clone
+			domain_cloned.owners << user_id
+			@domains_by_name.update domain_cloned
+			Response::DomainChanged.new domain_cloned
 		elsif domain = @domains_by_transfer_key.get? uuid
 			if domain.owners.includes? user_id
 				return Response::Error.new "You already own this domain."
 			end
-			domain.transfer_key = nil
-			domain.owners = [user_id]
-			@domains_by_name.update domain
-			Response::DomainChanged.new domain
+			# Clone the domain so the old `transfer_key` still exists in the old version.
+			domain_cloned = domain.clone
+			domain_cloned.transfer_key = nil
+			domain_cloned.owners = [user_id]
+			@domains_by_name.update domain_cloned
+			Response::DomainChanged.new domain_cloned
 		else
 			Response::Error.new "There is no key with this UUID."
 		end
@@ -274,6 +283,8 @@ class DNSManager::Storage
 
 		zone.rr_not_readonly! rr.rrid
 
+		zone_clone = zone.clone
+
 		# Test RR validity.
 		rr.get_errors.tap do |errors|
 			unless errors.empty?
@@ -282,9 +293,9 @@ class DNSManager::Storage
 			end
 		end
 
-		zone.update_rr rr
+		zone_clone.update_rr rr
 
-		update_zone zone
+		update_zone zone_clone
 
 		Response::RRUpdated.new domain, rr
 	end
@@ -300,8 +311,10 @@ class DNSManager::Storage
 			tokens_by_uuid.delete token_uuid
 		end
 
-		zone.delete_rr rrid
-		update_zone zone
+		zone_clone = zone.clone
+
+		zone_clone.delete_rr rrid
+		update_zone zone_clone
 
 		Response::RRDeleted.new rrid
 	end
@@ -313,8 +326,9 @@ class DNSManager::Storage
 		domain = @domains_by_name.get domain_name
 		# The user isn't the only owner, just remove him from the list of owners.
 		if domain.owners.size > 1
-			domain.owners.select! { |o| o != user_id }
-			@domains_by_name.update_or_create domain_name, domain
+			domain_cloned = domain.clone
+			domain_cloned.owners.select! { |o| o != user_id }
+			@domains_by_name.update domain_cloned
 
 			# Not really a domain deletion, but that'll do the trick.
 			return Response::DomainDeleted.new domain_name
@@ -363,15 +377,16 @@ class DNSManager::Storage
 
 	def wipe_user_data(user_id : UserDataID)
 		domains_by_owners.get(user_id.to_s).each do |domain|
-			domain.owners.delete user_id
+			domain_cloned = domain.clone
+			domain_cloned.owners.delete user_id
 
 			# Remove the user's domain when he is the only owner.
-			if domain.owners.empty?
-				@domains_by_name.delete domain.name
-				@tokens_by_domain.delete domain.name
-				@zones_by_domain.delete domain.name
+			if domain_cloned.owners.empty?
+				@domains_by_name.delete domain_cloned.name
+				@tokens_by_domain.delete domain_cloned.name
+				@zones_by_domain.delete domain_cloned.name
 			else
-				@domains_by_name.update_or_create domain.name, domain
+				@domains_by_name.update domain_cloned
 			end
 		end
 	rescue e
@@ -441,10 +456,11 @@ class DNSManager::Storage
 
 		# 2. add token to the RR.
 		rr.token = token.uuid
-		zone.update_rr rr
+		zone_clone = zone.clone
+		zone_clone.update_rr rr
 
 		# 3. update the zone (no need to call `update_zone` to change the zone serial).
-		zones_by_domain.update_or_create zone.domain, zone
+		zones_by_domain.update zone_clone
 
 		# 4. if there is an old token, remove it.
 		if old_token_uuid = old_token
@@ -476,7 +492,7 @@ class DNSManager::Storage
 			return Response::Error.new "invalid ipv4" unless Zone.is_ipv4_address_valid? address
 			rr.target = address
 			zone.update_rr rr
-			zones_by_domain.update_or_create zone.domain, zone
+			update_zone zone
 			Response::Success.new
 		when Zone::AAAA
 			return Response::Error.new "invalid ipv6" unless Zone.is_ipv6_address_valid? address