diff --git a/extra/cantor/PKGBUILD b/extra/cantor/PKGBUILD
index e88723580..239f38e53 100644
--- a/extra/cantor/PKGBUILD
+++ b/extra/cantor/PKGBUILD
@@ -7,7 +7,7 @@
 
 pkgname=cantor
 pkgver=16.12.0
-pkgrel=1
+pkgrel=3
 pkgdesc="KDE Frontend to Mathematical Software"
 url="http://kde.org/applications/education/cantor/"
 arch=('i686' 'x86_64')
@@ -24,13 +24,19 @@ optdepends=('maxima: Maxima backend'
             'sagemath: SageMath backend')
 conflicts=('kdeedu-cantor')
 replaces=('kdeedu-cantor')
-source=("http://download.kde.org/stable/applications/${pkgver}/src/cantor-${pkgver}.tar.xz"{,.sig})
+source=("http://download.kde.org/stable/applications/${pkgver}/src/cantor-${pkgver}.tar.xz"{,.sig}
+        cantor-python3.6.patch::"https://cgit.kde.org/cantor.git/patch/?id=2c67377")
 sha1sums=('58498ba930688dd948c9796e06998bde9ec5c160'
-          'SKIP')
+          'SKIP'
+          '4778cda4f5289f0bd9ab1c7943c9e16c7f82197a')
 validpgpkeys=(CA262C6C83DE4D2FB28A332A3A6A4DB839EAA6D7) # Albert Astals Cid <aacid@kde.org>
 
 prepare() {
   mkdir -p build
+
+# Fix python3 backend build with python 3.6
+  cd $pkgname-$pkgver
+  patch -p1 -i ../cantor-python3.6.patch
 }
 
 build() {