diff --git a/fm/generateMap.lua b/fm/generateMap.lua
index 8e2fc46..a934470 100644
--- a/fm/generateMap.lua
+++ b/fm/generateMap.lua
@@ -19,7 +19,7 @@ function fm.generateMap(data)
     local gridPixelSizes = {8, 16, 32, 64}
     local gridPixelSize = gridPixelSizes[data.gridSizeIndex]
 
-    local minZoomLevel = data.gridSizeIndex+1
+    local minZoomLevel = data.gridSizeIndex
     local maxZoomLevel = 0 -- default
 
     local resolutionArray = {8,16,32,64,128,256,512,1024,2048,4096,8192,16384,32768,65536,131072,262144,524288,1048576} -- resolution for each zoom level, lvl 0 is always 8x8 (256x256 pixels)