diff --git a/Modules/Filtering/ImageGradient/include/itkGradientImageFilter.h b/Modules/Filtering/ImageGradient/include/itkGradientImageFilter.h
index 4dfc0d87bb5..d5e37908be5 100644
--- a/Modules/Filtering/ImageGradient/include/itkGradientImageFilter.h
+++ b/Modules/Filtering/ImageGradient/include/itkGradientImageFilter.h
@@ -141,9 +141,12 @@ class ITK_TEMPLATE_EXPORT GradientImageFilter : public ImageToImageFilter<TInput
   }
 #endif
 
-  /** Allows to change the default boundary condition */
-  void
+#ifndef ITK_FUTURE_LEGACY_REMOVE
+  /** Allows to change the default boundary condition
+   * \note This filter takes ownership of the specified boundary condition object. */
+  [[deprecated("Deprecated in favor of `OverrideBoundaryCondition(std::unique_ptr<BoundaryConditionType>)`.")]] void
   OverrideBoundaryCondition(BoundaryConditionType * boundaryCondition);
+#endif
 
   /** Allows to change the default boundary condition */
   void
diff --git a/Modules/Filtering/ImageGradient/include/itkGradientImageFilter.hxx b/Modules/Filtering/ImageGradient/include/itkGradientImageFilter.hxx
index ed5c80c8cb7..1aa68b0ebc4 100644
--- a/Modules/Filtering/ImageGradient/include/itkGradientImageFilter.hxx
+++ b/Modules/Filtering/ImageGradient/include/itkGradientImageFilter.hxx
@@ -37,6 +37,7 @@ GradientImageFilter<TInputImage, TOperatorValueType, TOutputValueType, TOutputIm
   this->ThreaderUpdateProgressOff();
 }
 
+#ifndef ITK_FUTURE_LEGACY_REMOVE
 template <typename TInputImage, typename TOperatorValueType, typename TOutputValue, typename TOutputImage>
 void
 GradientImageFilter<TInputImage, TOperatorValueType, TOutputValue, TOutputImage>::OverrideBoundaryCondition(
@@ -44,6 +45,7 @@ GradientImageFilter<TInputImage, TOperatorValueType, TOutputValue, TOutputImage>
 {
   m_BoundaryCondition.reset(boundaryCondition);
 }
+#endif
 
 template <typename TInputImage, typename TOperatorValueType, typename TOutputValue, typename TOutputImage>
 void