diff --git a/CHANGELOG.md b/CHANGELOG.md
index f6ca9dffda46c9..643449b480b036 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 - Added support to checkpoint after training batches in `ModelCheckpoint` callback ([#6146](https://github.com/PyTorchLightning/pytorch-lightning/pull/6146))
 - Added a way to print to terminal without breaking up the progress bar ([#5470](https://github.com/PyTorchLightning/pytorch-lightning/pull/5470))
 
+- Added support to checkpoint after training batches in `ModelCheckpoint` callback ([#6146](https://github.com/PyTorchLightning/pytorch-lightning/pull/6146))
 
 ### Changed
 
diff --git a/pytorch_lightning/callbacks/model_checkpoint.py b/pytorch_lightning/callbacks/model_checkpoint.py
index 90ac0f12f7a9b2..89da66dedd2d5f 100644
--- a/pytorch_lightning/callbacks/model_checkpoint.py
+++ b/pytorch_lightning/callbacks/model_checkpoint.py
@@ -165,13 +165,9 @@ def __init__(
         every_n_epochs: int = 1,
         every_n_batches: int = -1,
         mode: str = "min",
-<<<<<<< HEAD
-        period: Optional[int] = None,
-=======
-        period: int = 1,
         every_n_epochs: int = 1,
         every_n_batches: int = -1,
->>>>>>> Update model_checkpoint.py
+        period: Optional[int] = None,
     ):
         super().__init__()
         self.monitor = monitor
diff --git a/tests/checkpointing/test_model_checkpoint.py b/tests/checkpointing/test_model_checkpoint.py
index 18fabf771556b4..0af2464469da1d 100644
--- a/tests/checkpointing/test_model_checkpoint.py
+++ b/tests/checkpointing/test_model_checkpoint.py
@@ -499,6 +499,36 @@ def test_none_monitor_top_k(tmpdir):
     ModelCheckpoint(dirpath=tmpdir, save_top_k=-1)
     ModelCheckpoint(dirpath=tmpdir, save_top_k=0)
 
+def test_invalid_every_n_epoch(tmpdir):
+    """ Test that an exception is raised for every_n_epochs = 0 or < -1. """
+    with pytest.raises(
+        MisconfigurationException, match=r'Invalid value for every_n_epochs=0*'
+    ):
+        ModelCheckpoint(dirpath=tmpdir, every_n_epochs=0)
+    with pytest.raises(
+        MisconfigurationException, match=r'Invalid value for every_n_epochs=-2*'
+    ):
+        ModelCheckpoint(dirpath=tmpdir, every_n_epochs=-2)
+
+    # These should not fail
+    ModelCheckpoint(dirpath=tmpdir, every_n_epochs=-1)
+    ModelCheckpoint(dirpath=tmpdir, every_n_epochs=3)
+
+def test_invalid_every_n_batches(tmpdir):
+    """ Test that an exception is raised for every_n_batches = 0 or < -1. """
+    with pytest.raises(
+        MisconfigurationException, match=r'Invalid value for every_n_batches=0*'
+    ):
+        ModelCheckpoint(dirpath=tmpdir, every_n_batches=0)
+    with pytest.raises(
+        MisconfigurationException, match=r'Invalid value for every_n_batches=-2*'
+    ):
+        ModelCheckpoint(dirpath=tmpdir, every_n_batches=-2)
+
+    # These should not fail
+    ModelCheckpoint(dirpath=tmpdir, every_n_batches=-1)
+    ModelCheckpoint(dirpath=tmpdir, every_n_batches=3)
+
 
 def test_none_monitor_save_last(tmpdir):
     """ Test that a warning appears for save_last=True with monitor=None. """