diff --git a/Dockerfile.ci b/Dockerfile.ci
index 15cd016073ca..07b0c6a0ab57 100644
--- a/Dockerfile.ci
+++ b/Dockerfile.ci
@@ -34,7 +34,7 @@ WORKDIR /workspace
 # Install NeMo requirements
 ARG TE_TAG=7d576ed25266a17a7b651f2c12e8498f67e0baea
 ARG MODELOPT_VERSION=0.13.0
-ARG MCORE_TAG=c7a1f82d761577e6ca0338d3521eac82f2aa0904
+ARG MCORE_TAG=338af51452a53982d202e8386db6233adad1ce86
 ARG APEX_TAG=810ffae374a2b9cb4b5c5e28eaeca7d7998fca0c
 RUN \
 --mount=type=bind,source=requirements,target=requirements \
diff --git a/examples/nlp/language_modeling/conf/megatron_gpt_config.yaml b/examples/nlp/language_modeling/conf/megatron_gpt_config.yaml
index 809ca30ca5ed..ea469fade004 100755
--- a/examples/nlp/language_modeling/conf/megatron_gpt_config.yaml
+++ b/examples/nlp/language_modeling/conf/megatron_gpt_config.yaml
@@ -174,7 +174,7 @@ model:
   fsdp_sharded_checkpoint: False # Store and load FSDP shared checkpoint.
 
   # Distributed checkpoint setup
-  dist_ckpt_format: 'zarr' # Set to 'torch_dist' to use PyTorch distributed checkpoint format.
+  dist_ckpt_format: 'torch_dist' # Set to 'torch_dist' to use PyTorch distributed checkpoint format.
   dist_ckpt_load_on_device: True # whether to load checkpoint weights directly on GPU or to CPU
   dist_ckpt_parallel_save: True # if true, each worker will write its own part of the dist checkpoint
   dist_ckpt_parallel_save_within_dp: False # if true, save will be parallelized only within a DP group (whole world otherwise), which might slightly reduce the save overhead
diff --git a/nemo/lightning/io/pl.py b/nemo/lightning/io/pl.py
index d0749fbeead7..6625ca0a1622 100644
--- a/nemo/lightning/io/pl.py
+++ b/nemo/lightning/io/pl.py
@@ -208,6 +208,13 @@ def _determine_dist_ckpt_save_strategy(self):
         are passed in config or in case of a fully parallel save in which case
         a parallelization wrapper is applied.
         """
+        if self.save_ckpt_format == 'zarr':
+            logging.warning(
+                f'`zarr` distributed checkpoint backend is deprecated.'
+                f' Distributed optimizer checkpoint saving might be extremely slow.'
+                f' Please switch to PyTorch Distributed format (model.dist_ckpt_format=torch_dist).'
+            )
+
         if self.async_save and self.save_ckpt_format != 'torch_dist':
             raise ValueError('Async dist-ckpt save supported only for torch_dist format')
 
diff --git a/nemo/utils/callbacks/dist_ckpt_io.py b/nemo/utils/callbacks/dist_ckpt_io.py
index 9348779051bb..1f4e949ec340 100644
--- a/nemo/utils/callbacks/dist_ckpt_io.py
+++ b/nemo/utils/callbacks/dist_ckpt_io.py
@@ -242,7 +242,7 @@ def from_config(cls, model_cfg: dict, async_save: bool = False):
                 it should be provided separately. Defaults to False.
         """
         return cls(
-            save_ckpt_format=model_cfg.get('dist_ckpt_format', 'zarr'),
+            save_ckpt_format=model_cfg.get('dist_ckpt_format', 'torch_dist'),
             load_directly_on_device=model_cfg.get('dist_ckpt_load_on_device', True),
             load_strictness=model_cfg.get('dist_ckpt_load_strictness', None),
             async_save=async_save,
@@ -360,6 +360,13 @@ def _determine_dist_ckpt_save_strategy(self):
         are passed in config or in case of a fully parallel save in which case
         a parallelization wrapper is applied.
         """
+        if self.save_ckpt_format == 'zarr':
+            logging.warning(
+                f'`zarr` distributed checkpoint backend is deprecated.'
+                f' Distributed optimizer checkpoint saving might be extremely slow.'
+                f' Please switch to PyTorch Distributed format (model.dist_ckpt_format=torch_dist).'
+            )
+
         if self.async_save and self.save_ckpt_format != 'torch_dist':
             raise ValueError('Async dist-ckpt save supported only for torch_dist format')