diff --git a/pyodide_lock/spec.py b/pyodide_lock/spec.py
index 9fdafa4..542fe1f 100644
--- a/pyodide_lock/spec.py
+++ b/pyodide_lock/spec.py
@@ -10,6 +10,7 @@ class InfoSpec(BaseModel):
     platform: str
     version: str
     python: str
+    abi_version: str | None = None
     model_config = ConfigDict(extra="forbid")