diff --git a/.gitignore b/.gitignore
index 1b05740..9c882b7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,2 @@
-
 __pycache__/
+*.egg-info/
diff --git a/pbcabi/model.py b/pbcabi/model.py
index 9aa21fb..ff3ebf2 100644
--- a/pbcabi/model.py
+++ b/pbcabi/model.py
@@ -67,7 +67,7 @@ class TypeSpec:
                 discriminant):
             type_spec = type_spec_read_from(reader)
             return type_spec
-        assert False, "Unknown discriminant: 0x{:02x}".format(discriminant)
+        assert False, "Unknown TypeSpec discriminant: 0x{:02x}".format(discriminant)
 
 
 @enforce_typing.enforce_types
@@ -232,6 +232,20 @@ class MapTypeSpec(TypeSpec):
     type_key: TypeSpec
     type_value: TypeSpec
 
+@enforce_typing.enforce_types
+@dataclasses.dataclass(frozen=True, slots=True)
+class AvlTreeTypeSpec(MapTypeSpec):
+    '''
+    Type spec for AVL-tree. Avl trees does not store data inline.
+    '''
+    DISCRIMINANT = 0x19
+
+@enforce_typing.enforce_types
+@dataclasses.dataclass(frozen=True, slots=True)
+class InlineMapTypeSpec(MapTypeSpec):
+    '''
+    Type spec for a dynamically-sized map from some type to another type.
+    '''
     DISCRIMINANT = 0x0f
 
     @staticmethod
@@ -376,7 +390,7 @@ TYPE_SPEC_SUBTYPE_READ_FROM_BY_DISCRIMINANT = {
     v.value: simple_type_spec_read_from(v) for v in SimpleType
 } | {
     t.DISCRIMINANT: t.read_from for t in
-    [VecTypeSpec, MapTypeSpec, SetTypeSpec, ArrayTypeSpec, OptionTypeSpec]
+    [VecTypeSpec, InlineMapTypeSpec, AvlTreeTypeSpec, SetTypeSpec, ArrayTypeSpec, OptionTypeSpec]
 }
 
 
@@ -417,6 +431,7 @@ class FnKind(Enum):
     ZK_USER_VAR_OPENED = 0x15
     ZK_ATTESTATION_COMPLETE = 0x16
     ZK_SECRET_INPUT_WITH_EXPLICIT_TYPE = 0x17
+    ZK_EVM_EXTERNAL_EVENT = 0x18
 
     @staticmethod
     def read_from(reader: BinaryReader):
@@ -427,7 +442,7 @@ class FnKind(Enum):
         if found := [kind for kind in FnKind if kind.value == discriminant]:
             assert len(found) == 1
             return found[0]
-        assert False, "Unknown discriminant: 0x{:02x}".format(discriminant)
+        assert False, "Unknown FnKind discriminant: 0x{:02x}".format(discriminant)
 
 
 @enforce_typing.enforce_types
@@ -675,6 +690,7 @@ class FileAbi:
         version_client = Version.read_from(reader)
 
         assert version_client >= Version(5, 0, 0), version_client
+        assert version_client <= Version(5, 4, 0), version_client
 
         contract = ContractAbi.read_from(reader)
         return FileAbi(version_binder, version_client, contract)