diff --git a/altair/utils/schemapi.py b/altair/utils/schemapi.py
index b6cfa0ded..11332a1ea 100644
--- a/altair/utils/schemapi.py
+++ b/altair/utils/schemapi.py
@@ -71,6 +71,8 @@
 # class-level _class_is_valid_at_instantiation attribute to False
 DEBUG_MODE: bool = True
 
+jsonschema_version_str = importlib_version("jsonschema")
+
 
 def enable_debug_mode() -> None:
     global DEBUG_MODE
@@ -203,7 +205,6 @@ def _get_json_schema_draft_url(schema: dict) -> str:
 def _use_referencing_library() -> bool:
     """In version 4.18.0, the jsonschema package deprecated RefResolver in
     favor of the referencing library."""
-    jsonschema_version_str = importlib_version("jsonschema")
     return Version(jsonschema_version_str) >= Version("4.18")
 
 
diff --git a/tools/schemapi/schemapi.py b/tools/schemapi/schemapi.py
index 52d58d1d3..829f477cf 100644
--- a/tools/schemapi/schemapi.py
+++ b/tools/schemapi/schemapi.py
@@ -69,6 +69,8 @@
 # class-level _class_is_valid_at_instantiation attribute to False
 DEBUG_MODE: bool = True
 
+jsonschema_version_str = importlib_version("jsonschema")
+
 
 def enable_debug_mode() -> None:
     global DEBUG_MODE
@@ -201,7 +203,6 @@ def _get_json_schema_draft_url(schema: dict) -> str:
 def _use_referencing_library() -> bool:
     """In version 4.18.0, the jsonschema package deprecated RefResolver in
     favor of the referencing library."""
-    jsonschema_version_str = importlib_version("jsonschema")
     return Version(jsonschema_version_str) >= Version("4.18")