diff --git a/raml-parser-2/src/main/java/org/raml/v2/internal/impl/commons/grammar/BaseRamlGrammar.java b/raml-parser-2/src/main/java/org/raml/v2/internal/impl/commons/grammar/BaseRamlGrammar.java
index 7776cce5..749f2124 100644
--- a/raml-parser-2/src/main/java/org/raml/v2/internal/impl/commons/grammar/BaseRamlGrammar.java
+++ b/raml-parser-2/src/main/java/org/raml/v2/internal/impl/commons/grammar/BaseRamlGrammar.java
@@ -759,6 +759,6 @@ protected Rule protocols()
 
     protected Rule responseCodes()
     {
-        return range(Range.closed(100L, 599L));
+        return range(Range.closed(0L, 999L));
     }
 }
diff --git a/raml-parser-2/src/test/resources/org/raml/v2/parser/custom-http-status-codes/input.raml b/raml-parser-2/src/test/resources/org/raml/v2/parser/custom-http-status-codes/input.raml
new file mode 100644
index 00000000..81bbcb73
--- /dev/null
+++ b/raml-parser-2/src/test/resources/org/raml/v2/parser/custom-http-status-codes/input.raml
@@ -0,0 +1,7 @@
+#%RAML 1.0
+title: My API
+/resource:
+  get:
+    responses:
+      0:
+      999:
diff --git a/raml-parser-2/src/test/resources/org/raml/v2/parser/custom-http-status-codes/output.txt b/raml-parser-2/src/test/resources/org/raml/v2/parser/custom-http-status-codes/output.txt
new file mode 100644
index 00000000..c76a2794
--- /dev/null
+++ b/raml-parser-2/src/test/resources/org/raml/v2/parser/custom-http-status-codes/output.txt
@@ -0,0 +1,34 @@
+RamlDocumentNode (Start: 11 , End: 78, On: input.raml, Source: SYObjectNode)
+    KeyValueNodeImpl (Start: 11 , End: 24, On: input.raml)
+        SYStringNode: "title" (Start: 11 , End: 16, On: input.raml)
+        OverlayableObjectNodeImpl (Start: 18 , End: 24, On: input.raml, Source: SYStringNode)
+            KeyValueNodeImpl (Start: 11 , End: 24, On: input.raml)
+                StringNodeImpl: "value" (Start: -1 , End: -1)
+                OverlayableStringNode: "My API" (Start: 18 , End: 24, On: input.raml)
+    ResourceNode (Start: 25 , End: 78, On: input.raml, Source: KeyValueNodeImpl)
+        SYStringNode: "/resource" (Start: 25 , End: 34, On: input.raml)
+        SYObjectNode (Start: 38 , End: 78, On: input.raml)
+            MethodNode (Start: 38 , End: 78, On: input.raml, Source: KeyValueNodeImpl)
+                SYStringNode: "get" (Start: 38 , End: 41, On: input.raml)
+                SYObjectNode (Start: 47 , End: 78, On: input.raml)
+                    KeyValueNodeImpl (Start: 47 , End: 78, On: input.raml)
+                        SYStringNode: "responses" (Start: 47 , End: 56, On: input.raml)
+                        SYObjectNode (Start: 64 , End: 78, On: input.raml)
+                            ResponseNode (Start: 64 , End: 66, On: input.raml, Source: KeyValueNodeImpl)
+                                SYIntegerNode: 0 (Start: 64 , End: 65, On: input.raml)
+                                SYNullNode (Start: 66 , End: 66, On: input.raml)
+                            ResponseNode (Start: 73 , End: 77, On: input.raml, Source: KeyValueNodeImpl)
+                                SYIntegerNode: 999 (Start: 73 , End: 76, On: input.raml)
+                                SYNullNode (Start: 77 , End: 77, On: input.raml)
+                    KeyValueNodeImpl (Start: -1 , End: -1)
+                        StringNodeImpl: "displayName" (Start: -1 , End: -1)
+                        ObjectNodeImpl (Start: -1 , End: -1)
+                            KeyValueNodeImpl (Start: -1 , End: -1)
+                                StringNodeImpl: "value" (Start: -1 , End: -1)
+                                OverlayableStringNode: "get" (Start: -1 , End: -1, Source: SYStringNode)
+            KeyValueNodeImpl (Start: -1 , End: -1)
+                StringNodeImpl: "displayName" (Start: -1 , End: -1)
+                ObjectNodeImpl (Start: -1 , End: -1)
+                    KeyValueNodeImpl (Start: -1 , End: -1)
+                        StringNodeImpl: "value" (Start: -1 , End: -1)
+                        OverlayableStringNode: "/resource" (Start: -1 , End: -1, Source: SYStringNode)