diff --git a/src/transformers/models/longformer/modeling_longformer.py b/src/transformers/models/longformer/modeling_longformer.py
index 20a2e9d239e2..c35cf318c437 100755
--- a/src/transformers/models/longformer/modeling_longformer.py
+++ b/src/transformers/models/longformer/modeling_longformer.py
@@ -1770,23 +1770,31 @@ def forward(
 
         Returns:
 
-        Examples:
+        Mask filling example:
 
         ```python
-        >>> import torch
-        >>> from transformers import LongformerForMaskedLM, LongformerTokenizer
+        >>> from transformers import LongformerTokenizer, LongformerForMaskedLM
 
-        >>> model = LongformerForMaskedLM.from_pretrained("allenai/longformer-base-4096")
         >>> tokenizer = LongformerTokenizer.from_pretrained("allenai/longformer-base-4096")
+        >>> model = LongformerForMaskedLM.from_pretrained("allenai/longformer-base-4096")
+        ```
 
-        >>> SAMPLE_TEXT = " ".join(["Hello world! "] * 1000)  # long input document
-        >>> input_ids = torch.tensor(tokenizer.encode(SAMPLE_TEXT)).unsqueeze(0)  # batch of size 1
+        Let's try a very long input.
 
-        >>> attention_mask = None  # default is local attention everywhere, which is a good choice for MaskedLM
-        >>> # check `LongformerModel.forward` for more details how to set *attention_mask*
-        >>> outputs = model(input_ids, attention_mask=attention_mask, labels=input_ids)
-        >>> loss = outputs.loss
-        >>> prediction_logits = outputs.logits
+        ```python
+        >>> TXT = (
+        ...     "My friends are <mask> but they eat too many carbs."
+        ...     + " That's why I decide not to eat with them." * 300
+        ... )
+        >>> input_ids = tokenizer([TXT], return_tensors="pt")["input_ids"]
+        >>> logits = model(input_ids).logits
+
+        >>> masked_index = (input_ids[0] == tokenizer.mask_token_id).nonzero().item()
+        >>> probs = logits[0, masked_index].softmax(dim=0)
+        >>> values, predictions = probs.topk(5)
+
+        >>> tokenizer.decode(predictions).split()
+        ['healthy', 'skinny', 'thin', 'good', 'vegetarian']
         ```"""
         return_dict = return_dict if return_dict is not None else self.config.use_return_dict
 
@@ -1848,9 +1856,11 @@ def __init__(self, config):
     @add_start_docstrings_to_model_forward(LONGFORMER_INPUTS_DOCSTRING.format("batch_size, sequence_length"))
     @add_code_sample_docstrings(
         processor_class=_TOKENIZER_FOR_DOC,
-        checkpoint=_CHECKPOINT_FOR_DOC,
+        checkpoint="jpelhaw/longformer-base-plagiarism-detection",
         output_type=LongformerSequenceClassifierOutput,
         config_class=_CONFIG_FOR_DOC,
+        expected_output="'ORIGINAL'",
+        expected_loss=5.44,
     )
     def forward(
         self,
@@ -2114,9 +2124,11 @@ def __init__(self, config):
     @add_start_docstrings_to_model_forward(LONGFORMER_INPUTS_DOCSTRING.format("batch_size, sequence_length"))
     @add_code_sample_docstrings(
         processor_class=_TOKENIZER_FOR_DOC,
-        checkpoint=_CHECKPOINT_FOR_DOC,
+        checkpoint="brad1141/Longformer-finetuned-norm",
         output_type=LongformerTokenClassifierOutput,
         config_class=_CONFIG_FOR_DOC,
+        expected_output="['Evidence', 'Evidence', 'Evidence', 'Evidence', 'Evidence', 'Evidence', 'Evidence', 'Evidence', 'Evidence', 'Evidence', 'Evidence', 'Evidence']",
+        expected_loss=0.63,
     )
     def forward(
         self,
diff --git a/src/transformers/models/longformer/modeling_tf_longformer.py b/src/transformers/models/longformer/modeling_tf_longformer.py
index 124fe2c06fec..8f654ea84b18 100644
--- a/src/transformers/models/longformer/modeling_tf_longformer.py
+++ b/src/transformers/models/longformer/modeling_tf_longformer.py
@@ -2079,10 +2079,12 @@ def get_prefix_bias_name(self):
     @add_start_docstrings_to_model_forward(LONGFORMER_INPUTS_DOCSTRING.format("batch_size, sequence_length"))
     @add_code_sample_docstrings(
         processor_class=_TOKENIZER_FOR_DOC,
-        checkpoint=_CHECKPOINT_FOR_DOC,
+        checkpoint="allenai/longformer-base-4096",
         output_type=TFLongformerMaskedLMOutput,
         config_class=_CONFIG_FOR_DOC,
         mask="<mask>",
+        expected_output="' Paris'",
+        expected_loss=0.44,
     )
     def call(
         self,
@@ -2175,6 +2177,8 @@ def __init__(self, config, *inputs, **kwargs):
         checkpoint="allenai/longformer-large-4096-finetuned-triviaqa",
         output_type=TFLongformerQuestionAnsweringModelOutput,
         config_class=_CONFIG_FOR_DOC,
+        expected_output="' puppet'",
+        expected_loss=0.96,
     )
     def call(
         self,
@@ -2318,9 +2322,11 @@ def __init__(self, config, *inputs, **kwargs):
     @add_start_docstrings_to_model_forward(LONGFORMER_INPUTS_DOCSTRING.format("batch_size, sequence_length"))
     @add_code_sample_docstrings(
         processor_class=_TOKENIZER_FOR_DOC,
-        checkpoint=_CHECKPOINT_FOR_DOC,
+        checkpoint="hf-internal-testing/tiny-random-longformer",
         output_type=TFLongformerSequenceClassifierOutput,
         config_class=_CONFIG_FOR_DOC,
+        expected_output="'LABEL_1'",
+        expected_loss=0.69,
     )
     def call(
         self,
@@ -2556,9 +2562,11 @@ def __init__(self, config, *inputs, **kwargs):
     @add_start_docstrings_to_model_forward(LONGFORMER_INPUTS_DOCSTRING.format("batch_size, sequence_length"))
     @add_code_sample_docstrings(
         processor_class=_TOKENIZER_FOR_DOC,
-        checkpoint=_CHECKPOINT_FOR_DOC,
+        checkpoint="hf-internal-testing/tiny-random-longformer",
         output_type=TFLongformerTokenClassifierOutput,
         config_class=_CONFIG_FOR_DOC,
+        expected_output="['LABEL_1', 'LABEL_1', 'LABEL_1', 'LABEL_1', 'LABEL_1', 'LABEL_1', 'LABEL_1', 'LABEL_1', 'LABEL_1', 'LABEL_1', 'LABEL_1', 'LABEL_1', 'LABEL_1', 'LABEL_1', 'LABEL_1', 'LABEL_1', 'LABEL_1', 'LABEL_1', 'LABEL_1', 'LABEL_1']",
+        expected_loss=0.59,
     )
     def call(
         self,
diff --git a/utils/documentation_tests.txt b/utils/documentation_tests.txt
index 8d8c7eccf2cd..b22499e9d0bd 100644
--- a/utils/documentation_tests.txt
+++ b/utils/documentation_tests.txt
@@ -31,6 +31,8 @@ src/transformers/models/glpn/modeling_glpn.py
 src/transformers/models/gpt2/modeling_gpt2.py
 src/transformers/models/gptj/modeling_gptj.py
 src/transformers/models/hubert/modeling_hubert.py
+src/transformers/models/longformer/modeling_longformer.py
+src/transformers/models/longformer/modeling_tf_longformer.py
 src/transformers/models/marian/modeling_marian.py
 src/transformers/models/mbart/modeling_mbart.py
 src/transformers/models/mobilebert/modeling_mobilebert.py