diff --git a/cmake/YarpDoc.cmake b/cmake/YarpDoc.cmake
index 2c5eef1ce6..5631b05f0b 100644
--- a/cmake/YarpDoc.cmake
+++ b/cmake/YarpDoc.cmake
@@ -7,17 +7,6 @@
 
 include(CMakeDependentOption)
 
-if("${DOXYGEN_VERSION}" MATCHES "([0-9]+)\.([0-9]+)\.([0-9]+)")
-  set(DOXYGEN_VERSION_MAJOR ${CMAKE_MATCH_1})
-  set(DOXYGEN_VERSION_MINOR ${CMAKE_MATCH_2})
-  set(DOXYGEN_VERSION_PATCH ${CMAKE_MATCH_3})
-else()
-  message(WARNING "Unknown doxygen version")
-  set(DOXYGEN_VERSION_MAJOR 0)
-  set(DOXYGEN_VERSION_MINOR 0)
-  set(DOXYGEN_VERSION_PATCH 0)
-endif()
-
 find_file(DOXYGEN_PLANTUM_JAR
           NAMES plantuml.jar
           PATHS /usr/share
@@ -28,6 +17,17 @@ if(NOT DOXYGEN_PLANTUM_JAR)
 endif()
 
 if(DOXYGEN_FOUND)
+
+  if("${DOXYGEN_VERSION}" MATCHES "([0-9]+)\.([0-9]+)\.([0-9]+)")
+    set(DOXYGEN_VERSION_MAJOR ${CMAKE_MATCH_1})
+    set(DOXYGEN_VERSION_MINOR ${CMAKE_MATCH_2})
+    set(DOXYGEN_VERSION_PATCH ${CMAKE_MATCH_3})
+  else()
+    set(DOXYGEN_VERSION_MAJOR 0)
+    set(DOXYGEN_VERSION_MINOR 0)
+    set(DOXYGEN_VERSION_PATCH 0)
+  endif()
+
   option(YARP_DOXYGEN_HTML "Generate doxygen HTML output" ON)
   cmake_dependent_option(YARP_DOXYGEN_HTML_DOCSET "Generate doxygen docset output (for Apple's Xcode 3)" OFF
                          YARP_DOXYGEN_HTML OFF)