diff --git a/doc/CMakeLists.txt b/doc/CMakeLists.txt
index e72b7ac2298..4a9861f7a1d 100644
--- a/doc/CMakeLists.txt
+++ b/doc/CMakeLists.txt
@@ -47,6 +47,16 @@ set(SPHINX_ENV
   DOT_EXECUTABLE=${DOXYGEN_DOT_EXECUTABLE}
 )
 
+if(DEFINED ENV{ZEPHYR_DOXYGEN_OVERLAY})
+  if(EXISTS $ENV{ZEPHYR_DOXYGEN_OVERLAY})
+    set(INCLUDE_CUSTOM_FILE "@INCLUDE = $ENV{ZEPHYR_DOXYGEN_OVERLAY}")
+  else()
+    message(FATAL_ERROR "Zephyr Doxygen overlay $ENV{ZEPHYR_DOXYGEN_OVERLAY} does not exist!")
+  endif()
+else()
+  set(INCLUDE_CUSTOM_FILE "")
+endif()
+
 set(DOCS_CFG_DIR ${CMAKE_CURRENT_LIST_DIR})
 set(DOCS_DOCTREE_DIR ${CMAKE_CURRENT_BINARY_DIR}/doctrees)
 set(DOCS_BUILD_DIR ${CMAKE_CURRENT_BINARY_DIR})
diff --git a/doc/zephyr.doxyfile.in b/doc/zephyr.doxyfile.in
index 268f2337802..df01f7954c7 100644
--- a/doc/zephyr.doxyfile.in
+++ b/doc/zephyr.doxyfile.in
@@ -2816,3 +2816,5 @@ GENERATE_LEGEND        = YES
 # The default value is: YES.
 
 DOT_CLEANUP            = YES
+
+@INCLUDE_CUSTOM_FILE@