diff --git a/Marlin/example_configurations/BQ/Hephestos_2/Configuration.h b/Marlin/example_configurations/BQ/Hephestos_2/Configuration.h
index 0a3d86329c..4d4f2b030e 100644
--- a/Marlin/example_configurations/BQ/Hephestos_2/Configuration.h
+++ b/Marlin/example_configurations/BQ/Hephestos_2/Configuration.h
@@ -140,7 +140,7 @@
 #define EXTRUDERS 1
 
 // Generally expected filament diameter (1.75, 2.85, 3.0, ...). Used for Volumetric, Filament Width Sensor, etc.
-#define DEFAULT_NOMINAL_FILAMENT_DIA 3.0
+#define DEFAULT_NOMINAL_FILAMENT_DIA 1.75
 
 // For Cyclops or any "multi-extruder" that shares a single nozzle.
 //#define SINGLENOZZLE