diff --git a/singer_sdk/mapper.py b/singer_sdk/mapper.py
index 0214fe9e9..a0de52e01 100644
--- a/singer_sdk/mapper.py
+++ b/singer_sdk/mapper.py
@@ -484,6 +484,12 @@ def _init_functions_and_schema(  # noqa: PLR0912, PLR0915, C901
                     )
                     raise StreamMapConfigError(msg)
                 transformed_schema["properties"].pop(prop_key, None)
+                if "required" in transformed_schema:
+                    transformed_schema["required"] = [
+                        item
+                        for item in transformed_schema["required"]
+                        if item != prop_key
+                    ]
                 stream_map_parsed.append((prop_key, prop_def, None))
             elif isinstance(prop_def, str):
                 default_type: th.JSONTypeHelper = th.StringType()  # Fallback to string
diff --git a/tests/snapshots/mapped_stream/drop_property.jsonl b/tests/snapshots/mapped_stream/drop_property.jsonl
index 940cb86b6..f9d032b74 100644
--- a/tests/snapshots/mapped_stream/drop_property.jsonl
+++ b/tests/snapshots/mapped_stream/drop_property.jsonl
@@ -1,5 +1,5 @@
 {"type":"STATE","value":{}}
-{"type":"SCHEMA","stream":"mystream","schema":{"properties":{"count":{"type":["integer","null"]},"user":{"properties":{"id":{"type":["integer","null"]},"sub":{"properties":{"num":{"type":["integer","null"]},"custom_obj":{"type":["string","null"]}},"type":["object","null"]},"some_numbers":{"items":{"type":["number"]},"type":["array","null"]}},"type":["object","null"]}},"type":"object","required":["email"]},"key_properties":[]}
+{"type":"SCHEMA","stream":"mystream","schema":{"properties":{"count":{"type":["integer","null"]},"user":{"properties":{"id":{"type":["integer","null"]},"sub":{"properties":{"num":{"type":["integer","null"]},"custom_obj":{"type":["string","null"]}},"type":["object","null"]},"some_numbers":{"items":{"type":["number"]},"type":["array","null"]}},"type":["object","null"]}},"type":"object","required":[]},"key_properties":[]}
 {"type":"RECORD","stream":"mystream","record":{"count":21,"user":{"id":1,"sub":{"num":1,"custom_obj":"obj-hello"},"some_numbers":[3.14,2.718]}},"time_extracted":"2022-01-01T00:00:00+00:00"}
 {"type":"RECORD","stream":"mystream","record":{"count":13,"user":{"id":2,"sub":{"num":2,"custom_obj":"obj-world"},"some_numbers":[10.32,1.618]}},"time_extracted":"2022-01-01T00:00:00+00:00"}
 {"type":"RECORD","stream":"mystream","record":{"count":19,"user":{"id":3,"sub":{"num":3,"custom_obj":"obj-hello"},"some_numbers":[1.414,1.732]}},"time_extracted":"2022-01-01T00:00:00+00:00"}
diff --git a/tests/snapshots/mapped_stream/drop_property_null_string.jsonl b/tests/snapshots/mapped_stream/drop_property_null_string.jsonl
index 940cb86b6..f9d032b74 100644
--- a/tests/snapshots/mapped_stream/drop_property_null_string.jsonl
+++ b/tests/snapshots/mapped_stream/drop_property_null_string.jsonl
@@ -1,5 +1,5 @@
 {"type":"STATE","value":{}}
-{"type":"SCHEMA","stream":"mystream","schema":{"properties":{"count":{"type":["integer","null"]},"user":{"properties":{"id":{"type":["integer","null"]},"sub":{"properties":{"num":{"type":["integer","null"]},"custom_obj":{"type":["string","null"]}},"type":["object","null"]},"some_numbers":{"items":{"type":["number"]},"type":["array","null"]}},"type":["object","null"]}},"type":"object","required":["email"]},"key_properties":[]}
+{"type":"SCHEMA","stream":"mystream","schema":{"properties":{"count":{"type":["integer","null"]},"user":{"properties":{"id":{"type":["integer","null"]},"sub":{"properties":{"num":{"type":["integer","null"]},"custom_obj":{"type":["string","null"]}},"type":["object","null"]},"some_numbers":{"items":{"type":["number"]},"type":["array","null"]}},"type":["object","null"]}},"type":"object","required":[]},"key_properties":[]}
 {"type":"RECORD","stream":"mystream","record":{"count":21,"user":{"id":1,"sub":{"num":1,"custom_obj":"obj-hello"},"some_numbers":[3.14,2.718]}},"time_extracted":"2022-01-01T00:00:00+00:00"}
 {"type":"RECORD","stream":"mystream","record":{"count":13,"user":{"id":2,"sub":{"num":2,"custom_obj":"obj-world"},"some_numbers":[10.32,1.618]}},"time_extracted":"2022-01-01T00:00:00+00:00"}
 {"type":"RECORD","stream":"mystream","record":{"count":19,"user":{"id":3,"sub":{"num":3,"custom_obj":"obj-hello"},"some_numbers":[1.414,1.732]}},"time_extracted":"2022-01-01T00:00:00+00:00"}