diff --git a/changes/4641-jparise.md b/changes/4641-jparise.md
new file mode 100644
index 00000000000..b671f3c6209
--- /dev/null
+++ b/changes/4641-jparise.md
@@ -0,0 +1 @@
+Allow dict schemas to have both `patternProperties` and `additionalProperties`
diff --git a/pydantic/schema.py b/pydantic/schema.py
index e7af56f120d..1348fbd5eef 100644
--- a/pydantic/schema.py
+++ b/pydantic/schema.py
@@ -490,7 +490,7 @@ def field_type_schema(
             # Dict keys have a regex pattern
             # items_schema might be a schema or empty dict, add it either way
             f_schema['patternProperties'] = {regex.pattern: items_schema}
-        elif items_schema:
+        if items_schema:
             # The dict values are not simply Any, so they need a schema
             f_schema['additionalProperties'] = items_schema
     elif field.shape == SHAPE_TUPLE or (field.shape == SHAPE_GENERIC and not issubclass(field.type_, BaseModel)):
diff --git a/tests/test_schema.py b/tests/test_schema.py
index 143768a8005..60e31776098 100644
--- a/tests/test_schema.py
+++ b/tests/test_schema.py
@@ -1654,7 +1654,13 @@ class Foo(BaseModel):
         'title': 'Foo',
         'type': 'object',
         'properties': {
-            'a': {'type': 'object', 'title': 'A', 'default': {}, 'patternProperties': {regex_str: {'type': 'string'}}}
+            'a': {
+                'type': 'object',
+                'title': 'A',
+                'default': {},
+                'additionalProperties': {'type': 'string'},
+                'patternProperties': {regex_str: {'type': 'string'}},
+            }
         },
     }