diff --git a/Device/Unit/IUnitConverter.h b/Device/Unit/IUnitConverter.h
index 9440faa8bd9c6c13a4a26659703dca31aa0c1ab8..7f8b9d7f13331533ad4637abc40e77472524313f 100644
--- a/Device/Unit/IUnitConverter.h
+++ b/Device/Unit/IUnitConverter.h
@@ -58,7 +58,6 @@ public:
 
     virtual std::vector<Axes::Units> availableUnits() const = 0;
     virtual Axes::Units defaultUnits() const = 0;
-    Axes::Units substituteDefaultUnits(Axes::Units units) const;
 
 #ifndef SWIG
     virtual std::unique_ptr<IAxis> createConvertedAxis(size_t i_axis, Axes::Units units) const = 0;
@@ -69,6 +68,7 @@ public:
 #endif // SWIG
 
 protected:
+    Axes::Units substituteDefaultUnits(Axes::Units units) const;
 #ifndef SWIG
     [[noreturn]] void throwUnitsError(std::string method, std::vector<Axes::Units> available) const;
 #endif // SWIG
diff --git a/auto/Wrap/doxygenDevice.i b/auto/Wrap/doxygenDevice.i
index 8839794da3c457082ce57ccbcd74773e4a0e0dfe..0581d585e0edd54126d4c1158741a29f67e8c936 100644
--- a/auto/Wrap/doxygenDevice.i
+++ b/auto/Wrap/doxygenDevice.i
@@ -1495,9 +1495,6 @@ Returns zero-valued output data array in specified units.
 %feature("docstring")  IUnitConverter::defaultUnits "virtual Axes::Units IUnitConverter::defaultUnits() const =0
 ";
 
-%feature("docstring")  IUnitConverter::substituteDefaultUnits "Axes::Units IUnitConverter::substituteDefaultUnits(Axes::Units units) const
-";
-
 %feature("docstring")  IUnitConverter::createConvertedAxis "virtual std::unique_ptr<IAxis> IUnitConverter::createConvertedAxis(size_t i_axis, Axes::Units units) const =0
 ";