diff --git a/include/rtkFFTHilbertImageFilter.hxx b/include/rtkFFTHilbertImageFilter.hxx
index 926b8ec5d..5eba6a91c 100644
--- a/include/rtkFFTHilbertImageFilter.hxx
+++ b/include/rtkFFTHilbertImageFilter.hxx
@@ -6,7 +6,7 @@
  *  you may not use this file except in compliance with the License.
  *  You may obtain a copy of the License at
  *
- *         http://www.apache.org/licenses/LICENSE-2.0.txt
+ *         https://www.apache.org/licenses/LICENSE-2.0.txt
  *
  *  Unless required by applicable law or agreed to in writing, software
  *  distributed under the License is distributed on an "AS IS" BASIS,