diff --git a/csharp/Platform.Protocols.Lino.Tests/ParserTests.cs b/csharp/Platform.Protocols.Lino.Tests/ParserTests.cs
index 1106c9f..e6f5e08 100644
--- a/csharp/Platform.Protocols.Lino.Tests/ParserTests.cs
+++ b/csharp/Platform.Protocols.Lino.Tests/ParserTests.cs
@@ -221,11 +221,11 @@ public static void EmptyLinkWithParenthesesTest()
             Assert.Equal(target, formattedLinks);
         }
 
-        [Fact(Skip = "Not implemented yet")]
+        [Fact]
         public static void EmptyLinkWithEmptySelfReferenceTest()
         {
             var source = @"(:)";
-            var target = @"(:)";
+            var target = @"()";
             var parser = new Parser();
             var links = parser.Parse(source);
             var formattedLinks = links.Format();
diff --git a/csharp/Platform.Protocols.Lino/Parser.peg b/csharp/Platform.Protocols.Lino/Parser.peg
index 3ca28f7..da4a4a0 100644
--- a/csharp/Platform.Protocols.Lino/Parser.peg
+++ b/csharp/Platform.Protocols.Lino/Parser.peg
@@ -14,8 +14,8 @@ multiLineValueAndWhitespace <Link<string>> = value:referenceOrLink _ { value }
 multiLineValues <IList<Link<string>>> = _ list:multiLineValueAndWhitespace* { list }
 singleLineValueAndWhitespace <Link<string>> = __ value:referenceOrLink { value }
 singleLineValues <IList<Link<string>>> = list:singleLineValueAndWhitespace+ { list }
-singleLineLink <Link<string>> = __ id:(reference) __ ":" v:singleLineValues { new Link<string>(id, v) }
-multiLineLink <Link<string>> = "(" _ id:(reference) _ ":" v:multiLineValues _ ")" { new Link<string>(id, v) }
+singleLineLink <Link<string>> = __ id:(reference) __ ":" v:singleLineValues { new Link<string>(id, v) } / __ ":" v:singleLineValues { new Link<string>(null, v) }
+multiLineLink <Link<string>> = "(" _ id:(reference) _ ":" v:multiLineValues _ ")" { new Link<string>(id, v) } / "(" _ ":" v:multiLineValues _ ")" { new Link<string>(null, v) }
 singleLineValueLink <Link<string>> = v:singleLineValues { new Link<string>(v) }
 multiLineValueLink <Link<string>> = "(" v:multiLineValues _ ")" { new Link<string>(v) }
 pointLink <Link<string>> = id:(reference) { new Link<string>(id) }