diff --git a/NEWS b/NEWS
index 3b7ef4761..507f5d2e2 100644
--- a/NEWS
+++ b/NEWS
@@ -3,6 +3,7 @@ DFHack Future
         plugins will not be loaded if globals they specify as required are not located (should prevent some crashes)
     Fixes
         advfort works again
+        digfort: now checks file type and existence
         exportlegends: Fixed map export
         full-heal: Fixed a problem with selecting units in the GUI
         gui/hack-wish: Fixed restrictive material filters
diff --git a/scripts/digfort.rb b/scripts/digfort.rb
index 74db423d3..0d41649b3 100644
--- a/scripts/digfort.rb
+++ b/scripts/digfort.rb
@@ -1,70 +1,65 @@
 # designate an area for digging according to a plan in csv format
 
-raise "usage: digfort <plan filename>" if not $script_args[0]
-planfile = File.read($script_args[0])
+fname = $script_args[0].to_s
 
-if df.cursor.x == -30000
-	puts "place the game cursor to the top-left corner of the design"
-	throw :script_finished
+if not $script_args[0] then 
+    puts "  Usage: digfort <plan filename>"
+    throw :script_finished
+end
+if not fname[-4..-1] == ".csv" then
+    puts "  The plan file must be in .csv format."
+    throw :script_finished
+end
+if not File.file?(fname) then
+    puts "  The specified file does not exist."
+    throw :script_finished
 end
 
-# a sample CSV file
-# empty lines are ignored
-# a special comment with start(dx, dy) means the actual patterns starts at cursor.x-dx, cursor.y-dy
-# the CSV file should be saved in the main DF directory, alongside of Dwarf Fortress.exe
-sample_csv = <<EOS
-# start(3, 4)
- ,d,d,d,d,d,d
-d, , , , , , ,d
-d, , , , , , ,d
-d, ,d, , ,d, ,d
-h, , , , , , ,h
-h,h,h,h,h,h,h,h
-h,h, ,d,d, ,h,h
-h,h,h,h,h,h,h,h
- ,h,h,h,h,h,h 
- , , ,h,h,h
- , , , ,h,h
-EOS
+planfile = File.read(fname)
+
+if df.cursor.x == -30000
+    puts "place the game cursor to the top-left corner of the design and retry"
+    throw :script_finished
+end
 
 offset = [0, 0]
 tiles = []
 planfile.each_line { |l|
-	if l =~ /#.*start\s*\(\s*(-?\d+)\s*[,;]\s*(-?\d+)/
-		raise "Error: multiple start() comments" if offset != [0, 0]
-		offset = [$1.to_i, $2.to_i]
-	end
+    if l =~ /#.*start\s*\(\s*(-?\d+)\s*[,;]\s*(-?\d+)/
+        raise "Error: multiple start() comments" if offset != [0, 0]
+        offset = [$1.to_i, $2.to_i]
+    end
 
-	l = l.chomp.sub(/#.*/, '')
-	next if l == ''
-	tiles << l.split(/[;,]/).map { |t|
-		t = t.strip
-		(t[0] == ?") ? t[1..-2] : t
-	}
+    l = l.chomp.sub(/#.*/, '')
+    next if l == ''
+    tiles << l.split(/[;,]/).map { |t|
+        t = t.strip
+        (t[0] == ?") ? t[1..-2] : t
+    }
 }
 
-x = x0 = df.cursor.x - offset[0]
+x = df.cursor.x - offset[0]
 y = df.cursor.y - offset[1]
 z = df.cursor.z
 
 tiles.each { |line|
-	next if line.empty? or line == ['']
-	line.each { |tile|
-		t = df.map_tile_at(x, y, z)
-		s = t.shape_basic
-		case tile
-		when 'd'; t.dig(:Default) if s == :Wall
-		when 'u'; t.dig(:UpStair) if s == :Wall
-		when 'j'; t.dig(:DownStair) if s == :Wall or s == :Floor
-		when 'i'; t.dig(:UpDownStair) if s == :Wall
-		when 'h'; t.dig(:Channel) if s == :Wall or s == :Floor
-		when 'r'; t.dig(:Ramp) if s == :Wall
-		when 'x'; t.dig(:No)
-		end
-		x += 1
-	}
-	x = x0
-	y += 1
+    next if line.empty? or line == ['']
+    line.each { |tile|
+        t = df.map_tile_at(x, y, z)
+        s = t.shape_basic
+        case tile
+        when 'd'; t.dig(:Default) if s == :Wall
+        when 'u'; t.dig(:UpStair) if s == :Wall
+        when 'j'; t.dig(:DownStair) if s == :Wall or s == :Floor
+        when 'i'; t.dig(:UpDownStair) if s == :Wall
+        when 'h'; t.dig(:Channel) if s == :Wall or s == :Floor
+        when 'r'; t.dig(:Ramp) if s == :Wall
+        when 'x'; t.dig(:No)
+        end
+        x += 1
+    }
+    x = df.cursor.x - offset[0]
+    y += 1
 }
 
-puts 'done'
+puts '  done'