diff --git a/templates/tools/doxygen/Doxyfile.include b/templates/tools/doxygen/Doxyfile.include
index 879495aae8c..1391016348f 100644
--- a/templates/tools/doxygen/Doxyfile.include
+++ b/templates/tools/doxygen/Doxyfile.include
@@ -77,7 +77,8 @@ PROJECT_LOGO           =
 # entered, it will be relative to the location where doxygen was started. If
 # left blank the current directory will be used.
 
-OUTPUT_DIRECTORY       = doc/ref/${packagename.lower()}
+OUTPUT_DIRECTORY       = doc/ref/${
+		packagename.lower() + ('.internal' if internal else '')}
 
 # If the CREATE_SUBDIRS tag is set to YES then doxygen will create 4096 sub-
 # directories (in 2 levels) under the output directory of each output format and
diff --git a/tools/doxygen/Doxyfile.c++.internal b/tools/doxygen/Doxyfile.c++.internal
index 5d016a6069f..71e2d012bb0 100644
--- a/tools/doxygen/Doxyfile.c++.internal
+++ b/tools/doxygen/Doxyfile.c++.internal
@@ -60,7 +60,7 @@ PROJECT_LOGO           =
 # entered, it will be relative to the location where doxygen was started. If
 # left blank the current directory will be used.
 
-OUTPUT_DIRECTORY       = doc/ref/c++
+OUTPUT_DIRECTORY       = doc/ref/c++.internal
 
 # If the CREATE_SUBDIRS tag is set to YES then doxygen will create 4096 sub-
 # directories (in 2 levels) under the output directory of each output format and
diff --git a/tools/doxygen/Doxyfile.core.internal b/tools/doxygen/Doxyfile.core.internal
index 29328723b6f..3812f674f1f 100644
--- a/tools/doxygen/Doxyfile.core.internal
+++ b/tools/doxygen/Doxyfile.core.internal
@@ -60,7 +60,7 @@ PROJECT_LOGO           =
 # entered, it will be relative to the location where doxygen was started. If
 # left blank the current directory will be used.
 
-OUTPUT_DIRECTORY       = doc/ref/core
+OUTPUT_DIRECTORY       = doc/ref/core.internal
 
 # If the CREATE_SUBDIRS tag is set to YES then doxygen will create 4096 sub-
 # directories (in 2 levels) under the output directory of each output format and