diff --git a/assets/themes/charging_stations/charging_stations.json b/assets/themes/charging_stations/charging_stations.json
index 8697b901a..91137ad15 100644
--- a/assets/themes/charging_stations/charging_stations.json
+++ b/assets/themes/charging_stations/charging_stations.json
@@ -57,7 +57,6 @@
   "startLon": 0,
   "startZoom": 1,
   "widenFactor": 1.5,
-  "defaultBackgroundId": "CartoDB.Voyager",
   "layers": [
     "charging_station"
   ]
diff --git a/assets/themes/cycle_infra/cycle_infra.json b/assets/themes/cycle_infra/cycle_infra.json
index 02297eb73..66d5839a9 100644
--- a/assets/themes/cycle_infra/cycle_infra.json
+++ b/assets/themes/cycle_infra/cycle_infra.json
@@ -45,7 +45,6 @@
     "cs": "Mapa, kde můžete prohlížet a upravovat věci související s cyklistickou infrastrukturou. Vytvořeno během #osoc21."
   },
   "hideFromOverview": false,
-  "defaultBackgroundId": "CartoDB.Voyager",
   "icon": "./assets/themes/cycle_infra/cycle-infra.svg",
   "startLat": 51,
   "startLon": 3.75,
diff --git a/assets/themes/cyclofix/cyclofix.json b/assets/themes/cyclofix/cyclofix.json
index 80d11b7e3..a99d009c7 100644
--- a/assets/themes/cyclofix/cyclofix.json
+++ b/assets/themes/cyclofix/cyclofix.json
@@ -36,7 +36,6 @@
   "credits": "Originally created during Open Summer of Code by Pieter Fiers, Thibault Declercq, Pierre Barban, Joost Schouppe and Pieter Vander Vennet",
   "icon": "./assets/themes/cyclofix/logo.svg",
   "startLat": 0,
-  "defaultBackgroundId": "CartoDB.Voyager",
   "startLon": 0,
   "startZoom": 1,
   "widenFactor": 2,
diff --git a/assets/themes/drinking_water/drinking_water.json b/assets/themes/drinking_water/drinking_water.json
index 95432c6d6..eb6cd55de 100644
--- a/assets/themes/drinking_water/drinking_water.json
+++ b/assets/themes/drinking_water/drinking_water.json
@@ -37,7 +37,6 @@
   },
   "icon": "./assets/themes/drinking_water/logo.svg",
   "startLat": 50.8465573,
-  "defaultBackgroundId": "CartoDB.Voyager",
   "startLon": 4.351697,
   "startZoom": 16,
   "widenFactor": 2,
diff --git a/assets/themes/education/education.json b/assets/themes/education/education.json
index a5860ec19..fc8aa5260 100644
--- a/assets/themes/education/education.json
+++ b/assets/themes/education/education.json
@@ -24,7 +24,6 @@
     "eu": "Hezkuntza",
     "pl": "Edukacja"
   },
-  "defaultBackgroundId": "CartoDB.Voyager",
   "startLat": 0,
   "startLon": 0,
   "startZoom": 0,
diff --git a/assets/themes/healthcare/healthcare.json b/assets/themes/healthcare/healthcare.json
index 70052f91e..488a88fe3 100644
--- a/assets/themes/healthcare/healthcare.json
+++ b/assets/themes/healthcare/healthcare.json
@@ -27,7 +27,6 @@
   },
   "icon": "./assets/layers/doctors/doctors.svg",
   "startLat": 50.8465573,
-  "defaultBackgroundId": "CartoDB.Voyager",
   "startLon": 4.351697,
   "startZoom": 16,
   "widenFactor": 2,
diff --git a/assets/themes/indoors/indoors.json b/assets/themes/indoors/indoors.json
index bef9d9bbe..60ae89052 100644
--- a/assets/themes/indoors/indoors.json
+++ b/assets/themes/indoors/indoors.json
@@ -27,7 +27,6 @@
   },
   "icon": "./assets/layers/entrance/entrance.svg",
   "startLat": 51.17181,
-  "defaultBackgroundId": "CartoDB.Voyager",
   "startLon": 4.144383,
   "startZoom": 14,
   "widenFactor": 2,
diff --git a/assets/themes/onwheels/onwheels.json b/assets/themes/onwheels/onwheels.json
index 86b61429b..38544e0b7 100644
--- a/assets/themes/onwheels/onwheels.json
+++ b/assets/themes/onwheels/onwheels.json
@@ -24,7 +24,6 @@
   },
   "icon": "./assets/themes/onwheels/crest.svg",
   "startLat": 50.86622,
-  "defaultBackgroundId": "CartoDB.Voyager",
   "startLon": 4.350103,
   "startZoom": 17,
   "widenFactor": 2,
diff --git a/assets/themes/openwindpowermap/openwindpowermap.json b/assets/themes/openwindpowermap/openwindpowermap.json
index 2b21d36c9..a453698d5 100644
--- a/assets/themes/openwindpowermap/openwindpowermap.json
+++ b/assets/themes/openwindpowermap/openwindpowermap.json
@@ -41,6 +41,5 @@
   "layers": [
     "windturbine"
   ],
-  "defaultBackgroundId": "CartoDB.Voyager",
   "credits": "Seppe Santens"
 }
\ No newline at end of file
diff --git a/assets/themes/osm_community_index/osm_community_index.json b/assets/themes/osm_community_index/osm_community_index.json
index 229f9aca4..16aa4e481 100644
--- a/assets/themes/osm_community_index/osm_community_index.json
+++ b/assets/themes/osm_community_index/osm_community_index.json
@@ -29,7 +29,6 @@
   },
   "icon": "./assets/themes/osm_community_index/osm.svg",
   "startLat": 50.8465573,
-  "defaultBackgroundId": "CartoDB.Voyager",
   "startLon": 4.351697,
   "startZoom": 16,
   "clustering": false,
diff --git a/assets/themes/postboxes/postboxes.json b/assets/themes/postboxes/postboxes.json
index 172977b86..de8889598 100644
--- a/assets/themes/postboxes/postboxes.json
+++ b/assets/themes/postboxes/postboxes.json
@@ -46,7 +46,6 @@
   "startLon": 9.9937,
   "startZoom": 13,
   "widenFactor": 1.5,
-  "defaultBackgroundId": "CartoDB.Voyager",
   "clustering": {
     "maxZoom": 14,
     "minNeededElements": 100
diff --git a/assets/themes/rainbow_crossings/rainbow_crossings.json b/assets/themes/rainbow_crossings/rainbow_crossings.json
index 689c29df9..043c87e28 100644
--- a/assets/themes/rainbow_crossings/rainbow_crossings.json
+++ b/assets/themes/rainbow_crossings/rainbow_crossings.json
@@ -24,7 +24,6 @@
   },
   "icon": "./assets/themes/rainbow_crossings/logo.svg",
   "startLat": 50.8465573,
-  "defaultBackgroundId": "CartoDB.Voyager",
   "startLon": 4.351697,
   "startZoom": 16,
   "widenFactor": 2,
diff --git a/assets/themes/walls_and_buildings/walls_and_buildings.json b/assets/themes/walls_and_buildings/walls_and_buildings.json
index 9175d774a..1c221af37 100644
--- a/assets/themes/walls_and_buildings/walls_and_buildings.json
+++ b/assets/themes/walls_and_buildings/walls_and_buildings.json
@@ -26,7 +26,6 @@
   },
   "icon": "./assets/layers/walls_and_buildings/walls_and_buildings.png",
   "startLat": 50.8465573,
-  "defaultBackgroundId": "CartoDB.Voyager",
   "startLon": 4.351697,
   "startZoom": 16,
   "widenFactor": 2,