diff --git a/src/python_training_project/__main__.py b/src/python_training_project/__main__.py
index a3cc794..b374114 100644
--- a/src/python_training_project/__main__.py
+++ b/src/python_training_project/__main__.py
@@ -7,7 +7,7 @@
 
 import click
 
-from python_training_project.calculate import sum
+from python_training_project.calculate import calc_sum
 
 log = logging.getLogger(__name__)
 
@@ -28,7 +28,7 @@ def cli():
 @click.argument("b", type=float)
 def cli_sum(a: float, b: float):
     """Show the sum of two numbers on the console."""
-    log.info("Sum of %f and %f is %f", a, b, sum(a, b))
+    log.info("Sum of %f and %f is %f", a, b, calc_sum(a, b))
 
 
 if __name__ == "__main__":
diff --git a/src/python_training_project/calculate.py b/src/python_training_project/calculate.py
index 38e024d..f85432e 100644
--- a/src/python_training_project/calculate.py
+++ b/src/python_training_project/calculate.py
@@ -3,7 +3,7 @@
 """
 
 
-def sum(a: float, b: float) -> float:
+def calc_sum(a: float, b: float) -> float:
     """Calculate the sum of two numbers."""
     return a + b
 
diff --git a/tests/test_calculate.py b/tests/test_calculate.py
index 5ebefb7..e18c5b1 100644
--- a/tests/test_calculate.py
+++ b/tests/test_calculate.py
@@ -1,13 +1,13 @@
-from python_training_project.calculate import sum
+from python_training_project.calculate import calc_sum
 
 
-def test_sum():
-    assert sum(1, 1) == 2
-    assert sum(2, 1) == 3
-    assert sum(1, 2) == 3
+def test_calc_sum():
+    assert calc_sum(1, 1) == 2
+    assert calc_sum(2, 1) == 3
+    assert calc_sum(1, 2) == 3
 
 
 def test_sum_negative():
-    assert sum(1, -1) == 0
-    assert sum(-1, 1) == 0
-    assert sum(-1, -1) == -2
+    assert calc_sum(1, -1) == 0
+    assert calc_sum(-1, 1) == 0
+    assert calc_sum(-1, -1) == -2