diff --git a/osiris/app.py b/osiris/app.py
index b2a9f12..e05a35d 100644
--- a/osiris/app.py
+++ b/osiris/app.py
@@ -1,7 +1,8 @@
+from enum import Enum
 import os
 
+import pandas as pd
 import numpy as np
-import polars as pl
 import typer
 
 from osiris.cairo.data_converter.data_converter import convert_to_cairo
@@ -14,17 +15,24 @@
 app = typer.Typer()
 
 
+class InputFormat(Enum):
+    CSV = 'CSV'
+    PARQUET = 'Parquet'
+    NUMPY = 'NumPy'
+    UNKNOWN = 'Unknown'
+
+
 def check_file_format(file_path):
     _, file_extension = os.path.splitext(file_path)
 
-    if file_extension in ['.csv']:
-        return 'CSV'
-    elif file_extension in ['.parquet']:
-        return 'Parquet'
-    elif file_extension in ['.npy']:
-        return 'NumPy'
+    if file_extension == '.csv':
+        return InputFormat.CSV
+    elif file_extension == '.parquet':
+        return InputFormat.PARQUET
+    elif file_extension == '.npy':
+        return InputFormat.NUMPY
     else:
-        return 'Unknown'
+        return InputFormat.UNKNOWN
 
 
 def load_data(input_file: str):
@@ -42,13 +50,13 @@ def load_data(input_file: str):
     input_format = check_file_format(input_file)
     match input_format:
         case InputFormat.CSV:
-            return pl.read_csv(input_file)
+            return pd.read_csv(input_file, header=None)
         case InputFormat.PARQUET:
-            return pl.read_parquet(input_file)
+            return pd.read_parquet(input_file)
         case InputFormat.NUMPY:
             return np.load(input_file)
         case _:
-            raise ValueError(f"Unsupported input format: {input_format}")
+            raise ValueError(f"Unsupported input format: {input_format.value}")
 
 
 def convert_to_numpy(data):
diff --git a/pyproject.toml b/pyproject.toml
index 0792dfa..d5fb72c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "giza-osiris"
-version = "0.2.0"
+version = "0.2.1"
 description = "Osiris is a Python library designed for efficient data conversion and management, primarily transforming data into Cairo programs"
 authors = ["Fran Algaba <fran@gizatech.xyz>"]
 readme = "README.md"
diff --git a/tests/data/simple_tensor.csv b/tests/data/simple_tensor.csv
new file mode 100644
index 0000000..ebb6763
--- /dev/null
+++ b/tests/data/simple_tensor.csv
@@ -0,0 +1,2 @@
+1,2
+3,4
diff --git a/tests/data/simple_tensor.npy b/tests/data/simple_tensor.npy
new file mode 100644
index 0000000..fbbcc39
Binary files /dev/null and b/tests/data/simple_tensor.npy differ
diff --git a/tests/data/simple_tensor.parquet b/tests/data/simple_tensor.parquet
new file mode 100644
index 0000000..f0ca502
Binary files /dev/null and b/tests/data/simple_tensor.parquet differ
diff --git a/tests/test_convert_to_numpy.py b/tests/test_convert_to_numpy.py
new file mode 100644
index 0000000..378ffb2
--- /dev/null
+++ b/tests/test_convert_to_numpy.py
@@ -0,0 +1,25 @@
+from osiris.app import convert_to_numpy, load_data
+from osiris.dtypes.input_output_formats import InputFormat
+
+import numpy as np
+
+
+def test_convert_to_numpy_from_csv():
+    data = load_data("tests/data/simple_tensor.csv")
+    numpy_array = convert_to_numpy(data)
+    assert np.array_equal(numpy_array, np.array(
+        [[1, 2], [3, 4]], dtype=np.uint32))
+
+
+def test_convert_to_numpy_from_parquet():
+    data = load_data("tests/data/simple_tensor.parquet")
+    numpy_array = convert_to_numpy(data)
+    assert np.array_equal(numpy_array, np.array(
+        [[1, 2], [3, 4]], dtype=np.uint32))
+
+
+def test_convert_to_numpy_from_npy():
+    data = load_data("tests/data/simple_tensor.npy")
+    numpy_array = convert_to_numpy(data)
+    assert np.array_equal(numpy_array, np.array(
+        [[1, 2], [3, 4]], dtype=np.uint32))