diff --git a/conanfile.py b/conanfile.py
index a80b2283..33c6d669 100644
--- a/conanfile.py
+++ b/conanfile.py
@@ -77,7 +77,7 @@ class UnitsConan(ConanFile):
             self.build_requires("catch2/2.13.4")
             self.build_requires("linear_algebra/0.7.0@conan-oss/stable")
             if self.options.build_docs:
-                self.build_requires("doxygen/1.8.20")
+                self.build_requires("doxygen/1.9.1")
 
     def validate(self):
         compiler = self.settings.compiler
diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index c24ee230..0cefc9de 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -1,7 +1,7 @@
 # Release notes
 
 - **0.8.0 WIP**
-
+  - build: doxygen updated to 1.9.1
 
 - **0.7.0 May 11, 2021**
   - (!) refactor: `ScalableNumber` renamed to `Representation`