diff --git a/experiments/run_slicegpt_perplexity.py b/experiments/run_slicegpt_perplexity.py
index 680773d8..8627633a 100755
--- a/experiments/run_slicegpt_perplexity.py
+++ b/experiments/run_slicegpt_perplexity.py
@@ -58,7 +58,12 @@ def argparser() -> argparse.Namespace:
     parser.add_argument(
         "--sparsity", type=float, default=0.0, help="A measure of how much slicing is applied (in the range [0, 1))"
     )
-    parser.add_argument("--round-interval", type=int, default=8, help="Interval for rounding the weights (the best value may depend on your hardware)")
+    parser.add_argument(
+        "--round-interval",
+        type=int,
+        default=8,
+        help="Interval for rounding the weights (the best value may depend on your hardware)",
+    )
     parser.add_argument("--eval-baseline", action="store_true", help="Evaluate the baseline model.")
     parser.add_argument("--eval-fused-model", action="store_true", help="Evaluate the fused model.")
     parser.add_argument("--ppl-only", action="store_true", help="Evaluate the loaded model without doing compression.")
@@ -203,8 +208,10 @@ def reset_model_device() -> None:
     # compute new embedding dimension given the desired sparsity level
     new_embedding_dimension = int((1 - args.sparsity) * model_adapter.hidden_size)
     # round (down) to the nearest multiple of round_interval
-    new_embedding_dimension = new_embedding_dimension - (new_embedding_dimension % args.round_interval) 
-    logging.info(f"New embedding dimension: {new_embedding_dimension} (sparsity {100*(1 - new_embedding_dimension / model_adapter.hidden_size):.4f} %)")
+    new_embedding_dimension = new_embedding_dimension - (new_embedding_dimension % args.round_interval)
+    logging.info(
+        f"New embedding dimension: {new_embedding_dimension} (sparsity {100*(1 - new_embedding_dimension / model_adapter.hidden_size):.4f} %)"
+    )
 
     ignore_tokens = [tokenizer.pad_token_id]
     rotate.rotate_and_slice(model_adapter, train_loader, new_embedding_dimension, ignore_tokens=ignore_tokens)
diff --git a/tests/test_opt.py b/tests/test_opt.py
new file mode 100644
index 00000000..03278f18
--- /dev/null
+++ b/tests/test_opt.py
@@ -0,0 +1,58 @@
+import torch
+
+from slicegpt import data_utils, gpu_utils, hf_utils, layernorm_fusion, rotate
+
+
+def test_opt_125m(sparsity=0.2, ppl_upper_limit=36):
+    """A complete test of OPT 125m, end-to-end. Includes:
+    - loading the model
+    - loading the calibration data
+    - layernorm fusion & module replacement
+    - slicing
+    - ppl evaluation (ppl is verified to be close to published value)
+
+    The intention of this test is that it should represent a complete run of SliceGPT,
+    but on a model small enough to run on CPU in a few minutes.
+    """
+    # get model
+    model_adapter, tokenizer = hf_utils.get_model_and_tokenizer("facebook/opt-125m", dtype=torch.float32)
+    model = model_adapter.model
+
+    # prepare data
+    train_dataset, test_dataset = data_utils.get_dataset("wikitext2")
+    train_loader = data_utils.prepare_dataloader(
+        dataset=train_dataset,
+        tokenizer=tokenizer,
+        max_seqlen=model.seqlen,
+        batch_size=1,
+        nsamples=128,
+        varied_seqlen=False,
+        seed=42,
+    )
+    test_loader = data_utils.prepare_dataloader(
+        dataset=test_dataset,
+        tokenizer=tokenizer,
+        max_seqlen=model_adapter.seqlen,
+        batch_size=1,
+        varied_seqlen=False,
+        seed=42,
+    )
+
+    # replace modules with compressible equivalents
+    layernorm_fusion.replace_layers(model_adapter)
+
+    # fuse layernorms and add rotations to skip connections
+    layernorm_fusion.fuse_modules(model_adapter)
+
+    # compute new embedding dimension given the desired sparsity level
+    new_embedding_dimension = int((1 - sparsity) * model_adapter.hidden_size)
+
+    # run slicing
+    ignore_tokens = [tokenizer.pad_token_id]
+    rotate.rotate_and_slice(model_adapter, train_loader, new_embedding_dimension, ignore_tokens=ignore_tokens)
+
+    # get ppl
+    dataset_ppl = gpu_utils.evaluate_ppl(model_adapter, test_loader)
+
+    # check that ppl is close to published value
+    assert dataset_ppl < ppl_upper_limit