diff --git a/configure.ac b/configure.ac
index e75d4706..0fa62df0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -359,6 +359,15 @@ AC_SUBST(DOCSDIR)
 AC_SUBST(AVR_LIBC_USER_MANUAL)
 AC_SUBST(DOC_INST_DIR)
 
+dnl Used in doc/api's doxygen.config.in::MAN_EXTENSION and Makefile.am.
+AC_ARG_WITH([man-page],
+  [AS_HELP_STRING([--with-man-page=],dnl
+                  [set man page for AVR-LibC documentation (default: 3avr)])],
+  [MAN_PAGE=$withval],
+  [MAN_PAGE=3avr])
+AC_MSG_NOTICE([Using man page $MAN_PAGE])
+AC_SUBST(MAN_PAGE)
+
 dnl Consumed by doc/api/doxygen.config.in::ENABLED_SECTIONS.
 AC_MSG_CHECKING([for git branch])
 the_git_branch=`(cd ${srcdir}; git rev-parse --abbrev-ref HEAD 2> /dev/null)`
diff --git a/doc/api/Makefile.am b/doc/api/Makefile.am
index 9baf9ff9..c17140cc 100644
--- a/doc/api/Makefile.am
+++ b/doc/api/Makefile.am
@@ -242,8 +242,8 @@ install-dox-pdf: dox-pdf
 	$(INSTALL_DATA) $(USER_MANUAL).pdf $(DOC_INST_DIR)/$(USER_MANUAL).pdf
 
 install-dox-man: dox-html
-	$(mkinstalldirs) $(DESTDIR)$(mandir)/man3
-	$(INSTALL_DATA) man/man3/*.3 $(DESTDIR)$(mandir)/man3
+	$(mkinstalldirs) $(DESTDIR)$(mandir)/man@MAN_PAGE@
+	$(INSTALL_DATA) man/man@MAN_PAGE@/*.@MAN_PAGE@ $(DESTDIR)$(mandir)/man@MAN_PAGE@
 
 .PHONY: html latex pdf demo demo-examples \
 	dox-html dox-pdf install-pdf install-html \
diff --git a/doc/api/doxygen.config.in b/doc/api/doxygen.config.in
index 97f028b0..73a593cf 100644
--- a/doc/api/doxygen.config.in
+++ b/doc/api/doxygen.config.in
@@ -1822,7 +1822,7 @@ MAN_OUTPUT             = man
 # The default value is: .3.
 # This tag requires that the tag GENERATE_MAN is set to YES.
 
-MAN_EXTENSION          = .3
+MAN_EXTENSION          = .@MAN_PAGE@
 
 # The MAN_SUBDIR tag determines the name of the directory created within
 # MAN_OUTPUT in which the man pages are placed. If defaults to man followed by