diff --git a/protobuf/protobuf2/Protobuf2.g4 b/protobuf/protobuf2/Protobuf2.g4
index 437349b2d3..ce562e2715 100644
--- a/protobuf/protobuf2/Protobuf2.g4
+++ b/protobuf/protobuf2/Protobuf2.g4
@@ -266,7 +266,7 @@ constant
 
 // not specified in specification but used in tests
 blockLit
-    : LC (ident COLON constant)* RC
+    : LC (ident COLON constant (COMMA)?)* RC
     ;
 
 emptyStatement_
diff --git a/protobuf/protobuf2/examples/block.proto b/protobuf/protobuf2/examples/block.proto
new file mode 100644
index 0000000000..5db19068a2
--- /dev/null
+++ b/protobuf/protobuf2/examples/block.proto
@@ -0,0 +1,22 @@
+syntax = 'proto2';
+
+// Extracted from google/protobuf/descriptor.proto
+message FeatureSet {
+  enum FieldPresence {
+    FIELD_PRESENCE_UNKNOWN = 0;
+    EXPLICIT = 1;
+    IMPLICIT = 2;
+    LEGACY_REQUIRED = 3;
+  }
+  optional FieldPresence field_presence = 1 [
+    retention = RETENTION_RUNTIME,
+    targets = TARGET_TYPE_FIELD,
+    targets = TARGET_TYPE_FILE,
+    feature_support = {
+      edition_introduced: EDITION_2023,
+    },
+    edition_defaults = { edition: EDITION_LEGACY, value: "EXPLICIT" },
+    edition_defaults = { edition: EDITION_PROTO3, value: "IMPLICIT" },
+    edition_defaults = { edition: EDITION_2023, value: "EXPLICIT" }
+  ];
+}
\ No newline at end of file