diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5d37677c..8bcbb392 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,6 +19,10 @@ Changelog
 - added option to set up webhooks for actor builds
 - added logger with basic debugging info
 
+### Fixed
+
+- disallowed `NaN` and `Infinity` values in JSONs sent to the Apify API
+
 ### Internal changes
 
 - simplified retrying with exponential backoff
diff --git a/src/apify_client/_http_client.py b/src/apify_client/_http_client.py
index 71385df3..7a750292 100644
--- a/src/apify_client/_http_client.py
+++ b/src/apify_client/_http_client.py
@@ -96,7 +96,7 @@ def _prepare_request_call(
 
         # dump JSON data to string, so they can be gzipped
         if json:
-            data = jsonlib.dumps(json, ensure_ascii=False, default=str).encode('utf-8')
+            data = jsonlib.dumps(json, ensure_ascii=False, allow_nan=False, default=str).encode('utf-8')
             headers['Content-Type'] = 'application/json'
 
         if isinstance(data, (str, bytes, bytearray)):
diff --git a/src/apify_client/_utils.py b/src/apify_client/_utils.py
index 96145cc6..b69dc5e3 100644
--- a/src/apify_client/_utils.py
+++ b/src/apify_client/_utils.py
@@ -211,7 +211,7 @@ def _encode_key_value_store_record_value(value: Any, content_type: Optional[str]
             content_type = 'application/json; charset=utf-8'
 
     if 'application/json' in content_type and not _is_file_or_bytes(value) and not isinstance(value, str):
-        value = json.dumps(value, ensure_ascii=False, indent=2, default=str).encode('utf-8')
+        value = json.dumps(value, ensure_ascii=False, indent=2, allow_nan=False, default=str).encode('utf-8')
 
     return (value, content_type)