diff --git a/.github/doc.sh b/.github/doc.sh
index e7df309a..6120b4cf 100755
--- a/.github/doc.sh
+++ b/.github/doc.sh
@@ -2,6 +2,7 @@
 
 export here="$(dirname "${0}")"
 source "${here}/ubuntu-deps.env"
+sudo apt install doxygen
 
 echo Configure
           mkdir -p build
diff --git a/cmake/setup.cmake b/cmake/setup.cmake
index 7cabe95f..944eade0 100644
--- a/cmake/setup.cmake
+++ b/cmake/setup.cmake
@@ -2,7 +2,10 @@ set(SETUP_CMAKE_INCLUDED 1)
 
 set(protobuf_version "3.20.0")
 if(USE_DOXYGEN)
-    set(doxygen_dep "doxygen/1.9.4")
+    find_program(DOXYGEN_BIN doxygen)
+    if (NOT DOXYGEN_BIN)
+        set(doxygen_dep "doxygen/1.9.4")
+    endif()
 else()
     set(doxygen_dep "")
 endif()