diff --git a/spacy/language.py b/spacy/language.py
index 204508dc4..b0e85446d 100644
--- a/spacy/language.py
+++ b/spacy/language.py
@@ -31,8 +31,10 @@ from typing import (
     overload,
 )
 
+import numpy
 import srsly
 from thinc.api import Config, CupyOps, Optimizer, get_current_ops
+from thinc.util import convert_recursive
 
 from . import about, ty, util
 from .errors import Errors, Warnings
@@ -2221,12 +2223,22 @@ class Language:
 
         DOCS: https://spacy.io/api/language#to_disk
         """
+        def _dump_meta(path, meta) -> None:
+            """Helper function for to_disk. It's not entirely clear why this is
+            necessary: we're seeing numpy.float32 values in the Ukraining trf
+            model meta, maybe it'll happen elsewhere as well -- but it seems
+            to originate from the specific transformer code being used by that
+            model.
+            """
+            meta = convert_recursive(lambda v: isinstance(v, numpy.float32), lambda v: float(v), dict(meta))
+            srsly.write_json(path, meta)
+
         path = util.ensure_path(path)
         serializers = {}
         serializers["tokenizer"] = lambda p: self.tokenizer.to_disk(  # type: ignore[union-attr]
             p, exclude=["vocab"]
         )
-        serializers["meta.json"] = lambda p: srsly.write_json(p, self.meta)
+        serializers["meta.json"] = _dump_meta
         serializers["config.cfg"] = lambda p: self.config.to_disk(p)
         for name, proc in self._components:
             if name in exclude:
@@ -2334,10 +2346,20 @@ class Language:
 
         DOCS: https://spacy.io/api/language#to_bytes
         """
+        def _dump_meta() -> str:
+            """Helper function for to_disk. It's not entirely clear why this is
+            necessary: we're seeing numpy.float32 values in the Ukraining trf
+            model meta, maybe it'll happen elsewhere as well -- but it seems
+            to originate from the specific transformer code being used by that
+            model.
+            """
+            meta = convert_recursive(lambda v: isinstance(v, numpy.float32), lambda v: float(v), dict(self.meta))
+            return srsly.json_dumps(meta)
+
         serializers: Dict[str, Callable[[], bytes]] = {}
         serializers["vocab"] = lambda: self.vocab.to_bytes(exclude=exclude)
         serializers["tokenizer"] = lambda: self.tokenizer.to_bytes(exclude=["vocab"])  # type: ignore[union-attr]
-        serializers["meta.json"] = lambda: srsly.json_dumps(self.meta)
+        serializers["meta.json"] = _dump_meta
         serializers["config.cfg"] = lambda: self.config.to_bytes()
         for name, proc in self._components:
             if name in exclude:
@@ -2427,7 +2449,6 @@ class DisabledPipes(list):
             self.nlp.enable_pipe(name)
         self[:] = []
 
-
 def _copy_examples(
     examples: Iterable[Example], *, copy_x: bool = True, copy_y: bool = False
 ) -> List[Example]: