diff --git a/mozilla-ublock-origin-python3.patch b/mozilla-ublock-origin-python3.patch
new file mode 100644
index 0000000..24b37ee
--- /dev/null
+++ b/mozilla-ublock-origin-python3.patch
@@ -0,0 +1,12 @@
+diff -up uBlock-1.28.2/tools/make-firefox.sh.py3 uBlock-1.28.2/tools/make-firefox.sh
+--- uBlock-1.28.2/tools/make-firefox.sh.py3	2020-07-11 15:26:44.000000000 +0200
++++ uBlock-1.28.2/tools/make-firefox.sh	2020-07-13 13:16:00.501025776 +0200
+@@ -34,7 +34,7 @@ rm $DES/js/vapi-usercss.pseudo.js
+ rm $DES/img/icon_128.png
+ 
+ echo "*** uBlock0.firefox: Generating meta..."
+-python tools/make-firefox-meta.py $DES/
++python3 tools/make-firefox-meta.py $DES/
+ 
+ if [ "$1" = all ]; then
+     echo "*** uBlock0.firefox: Creating package..."
diff --git a/mozilla-ublock-origin.spec b/mozilla-ublock-origin.spec
index 4bcff7d..32e9601 100644
--- a/mozilla-ublock-origin.spec
+++ b/mozilla-ublock-origin.spec
@@ -23,6 +23,8 @@ Source2:        uAssets-%{uAssets_commit}.tar.gz
 # generate a free one with the mktarball.sh script below
 Source10:       uAssets-mktarball.sh
 Patch0:         %{name}-nonfree.patch
+# call python3 instead of python
+Patch1:         %{name}-python3.patch
 
 Requires:       mozilla-filesystem
 BuildArch:      noarch
@@ -58,6 +60,7 @@ mkdir uAssets
 tar -xz -C uAssets --strip-components=1 -f %{SOURCE2}
 pushd uBlock-%{version}
 %patch0 -p1
+%patch1 -p1
 rm src/{js/wasm,lib/{lz4,publicsuffixlist/wasm}}/*.wasm
 popd
 
@@ -87,6 +90,9 @@ appstream-util validate-relax --nonet %{buildroot}%{_metainfodir}/%{name}.metain
 %{_metainfodir}/%{name}.metainfo.xml
 
 %changelog
+* Mon Jul 13 2020 Dominik Mierzejewski <rpm@greysector.net> - 1.28.2-2
+- use python3 in build script explicitly
+
 * Sun Jul 12 2020 Dominik Mierzejewski <rpm@greysector.net> - 1.28.2-1
 - update to 1.28.2 (#1835275)
 - "build" from upstream "source" directly