diff --git a/structuralcodes/materials/concrete/_concreteEC2_2004.py b/structuralcodes/materials/concrete/_concreteEC2_2004.py
index 060298f1..f60f92bb 100644
--- a/structuralcodes/materials/concrete/_concreteEC2_2004.py
+++ b/structuralcodes/materials/concrete/_concreteEC2_2004.py
@@ -392,11 +392,11 @@ def eps_cu1(self) -> float:
             float: The maximum strength at failure of concrete.
 
         Note:
-            The returned value is derived from fcm if eps_cu1 is not manually
+            The returned value is derived from fck if eps_cu1 is not manually
             provided when initializing the object.
         """
         if self._eps_cu1 is None:
-            return ec2_2004.eps_cu1(self.fcm)
+            return ec2_2004.eps_cu1(self.fck)
         return self._eps_cu1
 
     @property
diff --git a/tests/test_materials/test_concrete.py b/tests/test_materials/test_concrete.py
index 8c942150..01ed151a 100644
--- a/tests/test_materials/test_concrete.py
+++ b/tests/test_materials/test_concrete.py
@@ -4,6 +4,7 @@
 
 import pytest
 
+from structuralcodes.codes import ec2_2004
 from structuralcodes.materials.concrete import (
     Concrete,
     ConcreteEC2_2004,
@@ -120,3 +121,28 @@ def test_invalid_constitutive_law(concrete_type):
     )
     with pytest.raises(ValueError):
         concrete_type(fck=45, constitutive_law=invalid_constitutive_law)
+
+
+@pytest.mark.parametrize(
+    'fck',
+    (
+        35,
+        45,
+        55,
+        65,
+        70,
+    ),
+)
+def test_sargin_strains_ec2_2004(fck):
+    """Test that ConcreteEC2_2004 initializes the correct ultimate strain for
+    the Sargin law.
+    """
+    # Arrange
+    concrete = ConcreteEC2_2004(fck=fck)
+
+    # Act
+    eps_cu1_concrete = concrete.eps_cu1
+    eps_cu1_code = ec2_2004.eps_cu1(fck=fck)
+
+    # Assert
+    assert math.isclose(eps_cu1_concrete, eps_cu1_code)