diff --git a/changes/3234-cocolman.md b/changes/3234-cocolman.md
new file mode 100644
index 0000000000..b7f9cad68f
--- /dev/null
+++ b/changes/3234-cocolman.md
@@ -0,0 +1 @@
+Fix display of `extra` fields with model `__repr__`
diff --git a/pydantic/main.py b/pydantic/main.py
index 99d97008b1..fa501701f7 100644
--- a/pydantic/main.py
+++ b/pydantic/main.py
@@ -873,7 +873,9 @@ def __eq__(self, other: Any) -> bool:
             return self.dict() == other
 
     def __repr_args__(self) -> 'ReprArgs':
-        return [(k, v) for k, v in self.__dict__.items() if self.__fields__[k].field_info.repr]
+        return [
+            (k, v) for k, v in self.__dict__.items() if k not in self.__fields__ or self.__fields__[k].field_info.repr
+        ]
 
 
 _is_base_model_class_defined = True
diff --git a/tests/test_main.py b/tests/test_main.py
index 688cca127d..71da72544b 100644
--- a/tests/test_main.py
+++ b/tests/test_main.py
@@ -208,6 +208,16 @@ class Config:
     assert Model(a='10.2', b=12).dict() == {'a': 10.2, 'b': 12}
 
 
+def test_allow_extra_repr():
+    class Model(BaseModel):
+        a: float = ...
+
+        class Config:
+            extra = Extra.allow
+
+    assert str(Model(a='10.2', b=12)) == 'a=10.2 b=12'
+
+
 def test_forbidden_extra_success():
     class ForbiddenExtra(BaseModel):
         foo = 'whatever'