diff --git a/Makefile.am b/Makefile.am
index b01a28000848eafc8508a732f06f9cdb43ed3fdf..259ea1f8bc668c8a47cd6bbc73d9e0b457706ec0 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -467,6 +467,7 @@ EXTRA_DIST             += autogen.sh
 EXTRA_DIST             += build-aux/git-version-gen
 EXTRA_DIST             += ci/Jenkinsfile
 EXTRA_DIST             += data/capsule-mkstublib
+EXTRA_DIST             += doc/Building-libcapsule.txt
 EXTRA_DIST             += doc/Strategy.txt
 EXTRA_DIST             += doc/capsule-init-project.xml
 EXTRA_DIST             += doc/capsule-mkstublib.xml
diff --git a/doc/Building-libcapsule.txt b/doc/Building-libcapsule.txt
new file mode 100644
index 0000000000000000000000000000000000000000..db3d7c057d964df32a83dafe804a963b6a2dd4f0
--- /dev/null
+++ b/doc/Building-libcapsule.txt
@@ -0,0 +1,10 @@
+Building libcapsule from git requires GNU autoconf-archive macros. The
+oldest supported version is 20180313-1 from Debian 9 'stretch'. If your
+development system or container is older, unpack or clone a suitable
+version of autoconf-archive and use commands like:
+
+   libcapsule$ ACLOCAL_PATH=/path/to/autoconf-archive/m4 NOCONFIGURE=1 ./autogen.sh
+   libcapsule$ ./configure
+   libcapsule$ make
+
+Building from tarball releases removes this requirement.