diff --git a/ape_vyper/compiler.py b/ape_vyper/compiler.py
index 1b356acc..428e9d10 100644
--- a/ape_vyper/compiler.py
+++ b/ape_vyper/compiler.py
@@ -24,7 +24,7 @@
 from evm_trace.enums import CALL_OPCODES
 from packaging.specifiers import InvalidSpecifier, SpecifierSet
 from packaging.version import Version
-from pydantic import field_validator
+from pydantic import field_serializer, field_validator
 from vvm import compile_standard as vvm_compile_standard
 from vvm.exceptions import VyperError  # type: ignore
 
@@ -74,6 +74,13 @@ class VyperConfig(PluginConfig):
     def validate_version(cls, value):
         return SpecifierSet(_version_to_specifier(value)) if isinstance(value, str) else value
 
+    @field_serializer("version")
+    def serialize_version(self, value: Optional[SpecifierSet], _info) -> Optional[str]:
+        if version := value:
+            return str(version)
+
+        return None
+
 
 def _install_vyper(version: Version):
     try: