diff --git a/unpack_wafdir.py b/unpack_wafdir.py
new file mode 100644
index 0000000..7d3bdfa
--- /dev/null
+++ b/unpack_wafdir.py
@@ -0,0 +1,16 @@
+import os
+import sys
+
+src = os.path.abspath('waf')
+dst = os.path.abspath(sys.argv[1])
+
+sys.dont_write_bytecode = True
+
+try:
+    from importlib.machinery import SourceFileLoader
+    waf = SourceFileLoader('waf', src).load_module()
+except ImportError:
+    import imp
+    waf = imp.load_source('waf', src)
+
+waf.unpack_wafdir(dst, src)
diff --git a/waf.spec b/waf.spec
index 134d998..4d6e002 100644
--- a/waf.spec
+++ b/waf.spec
@@ -28,6 +28,7 @@ URL:            https://waf.io/
 # - docs/book, licensed CC BY-NC-ND
 # - Waf logos, licensed CC BY-NC
 Source:         waf-%{version}.stripped.tar.bz2
+Source1:        unpack_wafdir.py
 Patch0:         waf-1.8.11-libdir.patch
 Patch1:         waf-1.6.9-logo.patch
 Patch2:         waf-1.8.11-sphinx-no-W.patch
@@ -139,23 +140,18 @@ popd
 
 
 %install
-# use waf so it unpacks itself
-mkdir _temp ; pushd _temp
-cp -av ../waf .
-%{__python2} ./waf >/dev/null 2>&1
-pushd .waf-%{version}-*
+%{__python2} %{S:1} _temp
+pushd _temp
 find . -name '*.py' -printf '%%P\0' |
   xargs -0 -I{} install -m 0644 -p -D {} %{buildroot}%{_datadir}/waf/{}
 popd
 %if 0%{?with_python3}
-# use waf so it unpacks itself
-%{__python3} ./waf >/dev/null 2>&1
-pushd .waf3-%{version}-*
+%{__python3} %{S:1} _temp3
+pushd _temp3
 find . -name '*.py' -printf '%%P\0' |
   xargs -0 -I{} install -m 0644 -p -D {} %{buildroot}%{_datadir}/waf3/{}
 popd
 %endif # with_python3
-popd
 
 # install the frontend
 install -m 0755 -p -D waf-light %{buildroot}%{_bindir}/waf-%{python2_version}
@@ -248,6 +244,8 @@ rm -f docs/sphinx/build/html/.buildinfo
 %changelog
 * Fri Jul 20 2018 Thomas Moschny <thomas.moschny@gmx.de> - 1.9.14-2
 - Spec file cleanups.
+- Add unpack_wafdir.py (rhbz#1509550).
+
 * Sat Jul 14 2018 Fedora Release Engineering <releng@fedoraproject.org> - 1.9.14-1.3
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_29_Mass_Rebuild