diff --git a/.bumpversion.cfg b/.bumpversion.cfg
index 547eebd..c3e1d2d 100644
--- a/.bumpversion.cfg
+++ b/.bumpversion.cfg
@@ -1,5 +1,5 @@
 [bumpversion]
-current_version = 4.2.4
+current_version = 4.2.5
 tag = False
 commit = True
 
diff --git a/rcpchgrowth/measurement.py b/rcpchgrowth/measurement.py
index 338d1b8..9596f71 100644
--- a/rcpchgrowth/measurement.py
+++ b/rcpchgrowth/measurement.py
@@ -621,7 +621,7 @@ def __validate_measurement_method(
             elif observation_value_z_score < MINIMUM_BMI_ERROR_SDS:
                 raise ValueError(
                     f'The Body Mass Index measurement of {observation_value} kg/m² is below -15 SD and considered to be an error.')
-            elif observation_value_z_score > MAXIMUM_BMI_KGM2:
+            elif observation_value_z_score > MAXIMUM_BMI_ERROR_SDS:
                 raise ValueError(
                     f'The Body Mass Index measurement of {observation_value} kg/m² is above +15 SD and considered to be an error.')
             else:
diff --git a/setup.py b/setup.py
index 8967bdb..1c7a288 100644
--- a/setup.py
+++ b/setup.py
@@ -8,7 +8,7 @@
 
 setup(
     name="rcpchgrowth",
-    version="4.2.4",
+    version="4.2.5",
     description="SDS and Centile calculations for UK Growth Data",
     long_description=long_description,
     url="https://github.com/rcpch/digital-growth-charts/blob/master/README.md",