diff --git a/flatpak/README.md b/flatpak/README.md
index 6fbce0924437d89da045a132d66d5f4e6aee6ad0..4c336269002890fb6321cd0c194830c4c3f2d081 100644
--- a/flatpak/README.md
+++ b/flatpak/README.md
@@ -4,8 +4,8 @@ Install gajim flatpak repo
 --------------------------
 
 1. `flatpak --user remote-add --from gnome https://sdk.gnome.org/gnome.flatpakrepo`
-1. `flatpak --user install gnome org.gnome.Platform//3.24`
-1. `flatpak --user install gnome org.gnome.Sdk//3.24`
+1. `flatpak --user install gnome org.gnome.Platform//3.26`
+1. `flatpak --user install gnome org.gnome.Sdk//3.26`
 1. `flatpak-builder --repo=repo directory gajim/org.gajim.Gajim.json`
 1. `flatpak --user remote-add --no-gpg-verify repo repo`
 1. `flatpak --user install repo org.gajim.Gajim`
diff --git a/org.gajim.Gajim.json b/org.gajim.Gajim.json
index b6657012da8190fe74c2e07ca664c4c6ad3bdf5e..4df4c2c9f66a46b158237df089bb027a5b810576 100644
--- a/org.gajim.Gajim.json
+++ b/org.gajim.Gajim.json
@@ -1,7 +1,7 @@
 {
     "app-id": "org.gajim.Gajim",
     "runtime": "org.gnome.Platform",
-    "runtime-version": "3.24",
+    "runtime-version": "3.26",
     "sdk": "org.gnome.Sdk",
     "command": "gajim",
     "tags": ["nightly"],
@@ -17,12 +17,9 @@
         "--filesystem=home",
         "--socket=system-bus"
     ],
-    "build-options" : {
+    "build-options": {
         "cflags": "-O2 -g",
-        "cxxflags": "-O2 -g",
-        "env": {
-            "PYTHON": "python3"
-        }
+        "cxxflags": "-O2 -g"
     },
     "cleanup": [
         "/include",
@@ -58,8 +55,8 @@
             "sources": [
                 {
                     "type": "archive",
-                    "url": "https://pypi.python.org/packages/62/ea/f41d44e0a4222fe8317ffe1fe7a5c75ec71ca233b4067850567922f8b7be/cffi-1.11.3.tar.gz",
-                    "sha256": "8456abb0f892eb7d545f9ce94f4ba78d651365b1a59f9ce9ae7b5325a95dc698"
+                    "url": "https://files.pythonhosted.org/packages/10/f7/3b302ff34045f25065091d40e074479d6893882faef135c96f181a57ed06/cffi-1.11.4.tar.gz",
+                    "sha256": "df9083a992b17a28cd4251a3f5c879e0198bb26c9e808c4647e0a18739f1d11d"
                 }
             ]
         },
@@ -132,8 +129,8 @@
             "sources": [
                 {
                     "type": "archive",
-                    "url": "https://pypi.python.org/packages/41/5f/6da80400340fd48ba4ae1c673be4dc3821ac06cd9821ea60f9c7d32a009f/setuptools-38.4.0.zip",
-                    "sha256": "6501fc32f505ec5b3ed36ec65ba48f1b975f52cf2ea101c7b73a08583fd12f75"
+                    "url": "https://files.pythonhosted.org/packages/6c/54/f7e9cea6897636a04e74c3954f0d8335cc38f7d01e27eec98026b049a300/setuptools-38.5.1.zip",
+                    "sha256": "6425484c08e99a98a42209c25c3d325f749230b55284d66192784f941a7e6628"
                 }
             ]
         },
@@ -257,11 +254,21 @@
         /* Zeroconf support */
         {
             "name": "avahi",
-            "cleanup": [ "/bin", "/lib/avahi", "/share" ],
+            "cleanup": [
+                "/bin",
+                "/lib/avahi",
+                "/share"
+            ],
             "config-opts": [
-                "--with-distro=none", "--disable-qt3", "--disable-qt4",
-                "--disable-libdaemon", "--disable-pygtk", "--disable-gdbm",
-                "--disable-mono", "--disable-monodoc", "--disable-manpages"
+                "--with-distro=none",
+                "--disable-qt3",
+                "--disable-qt4",
+                "--disable-libdaemon",
+                "--disable-pygtk",
+                "--disable-gdbm",
+                "--disable-mono",
+                "--disable-monodoc",
+                "--disable-manpages"
             ],
             "sources": [
                 {
@@ -271,6 +278,60 @@
                 }
             ]
         },
+        /* OMEMO support */
+        {
+            "name": "protobuf",
+            "ensure-writable": [
+                "easy-install.pth",
+                "setuptools.pth"
+            ],
+            "buildsystem": "simple",
+            "build-commands": [
+                "python3 setup.py install --prefix=/app"
+            ],
+            "sources": [
+                {
+                    "type": "archive",
+                    "url": "https://files.pythonhosted.org/packages/14/03/ff5279abda7b46e9538bfb1411d42831b7e65c460d73831ed2445649bc02/protobuf-3.5.1.tar.gz",
+                    "sha256": "95b78959572de7d7fafa3acb718ed71f482932ddddddbd29ba8319c10639d863"
+                }
+            ]
+        },
+        {
+            "name": "python3-axolotl-curve25519",
+            "ensure-writable": [
+                "easy-install.pth"
+            ],
+            "buildsystem": "simple",
+            "build-commands": [
+                "python3 setup.py install --prefix=/app"
+            ],
+            "sources": [
+                {
+                    "type": "archive",
+                    "url": "https://files.pythonhosted.org/packages/69/e0/9605cac4c83c12d0bef5c2e9992f0bcbce4fae9a252899d545ccb7dc8717/python-axolotl-curve25519-0.1.tar.gz",
+                    "sha256": "c559f6a5bf51e869325b36bd83c14cccd7dec1c6e7599e797f9ba27a72d339c0"
+                }
+            ]
+        },
+        {
+            "name": "python3-axolotl",
+            "ensure-writable": [
+                "easy-install.pth",
+                "setuptools.pth"
+            ],
+            "buildsystem": "simple",
+            "build-commands": [
+                "python3 setup.py install --prefix=/app"
+            ],
+            "sources": [
+                {
+                    "type": "archive",
+                    "url": "https://files.pythonhosted.org/packages/7f/9d/410ce5c2322180cae7025e52e2f91f585d2be71f30ebbcfd605d2c9a1cd5/python-axolotl-0.1.39.tar.gz",
+                    "sha256": "9af9c937d0d05ebea414f1be79ecc7517cc3541a77101941e6a2a71bdd2b6e25"
+                }
+            ]
+        },
         {
             "name": "python3-nbxmpp",
             "buildsystem": "simple",
@@ -289,12 +350,18 @@
             "name": "gajim",
             "buildsystem": "simple",
             "build-commands": [
-                "pip3 install --prefix=/app --no-deps ."
+                "pip3 install --prefix=/app ."
             ],
             "sources": [
                 {
                     "type": "git",
                     "url": "https://dev.gajim.org/gajim/gajim.git"
+                },
+                {
+                    "type": "archive",
+                    "url": "https://ftp.gajim.org/plugins_1/plugin_installer.zip",
+                    "sha256": "7d5dcd9a5e05d214ca85651784bda732aac3b5c363a6e23529e6e777f9d24d42",
+                    "dest": "gajim/data/plugins/plugin_installer"
                 }
             ]
         }