diff --git a/tools/gen_display_resources.py b/tools/gen_display_resources.py
index 9ed829f7d37..f857754e95f 100644
--- a/tools/gen_display_resources.py
+++ b/tools/gen_display_resources.py
@@ -76,7 +76,7 @@ def _load_row(self, y, row):
     print("Font missing", missing, "characters", file=sys.stderr)
 
 tile_x, tile_y, dx, dy = f.get_bounding_box()
-total_bits = tile_x * len(all_characters)
+total_bits = tile_x * len(filtered_characters)
 total_bits += 32 - total_bits % 32
 bytes_per_row = total_bits // 8
 b = bytearray(bytes_per_row * tile_y)
@@ -283,7 +283,7 @@ def _load_row(self, y, row):
     .inline_tiles = false,
     .in_group = true
 }};
-""".format(len(all_characters), tile_x, tile_y)
+""".format(len(filtered_characters), tile_x, tile_y)
 )
 
 c_file.write(
@@ -311,7 +311,7 @@ def _load_row(self, y, row):
     .inline_tiles = false,
     .in_group = true
 }};
-""".format(len(all_characters), tile_x, tile_y)
+""".format(len(filtered_characters), tile_x, tile_y)
 )
 
 c_file.write(
@@ -345,7 +345,7 @@ def _load_row(self, y, row):
     .bitmask = 0x01,
     .read_only = true
 }};
-""".format(len(all_characters) * tile_x, tile_y, bytes_per_row / 4)
+""".format(len(filtered_characters) * tile_x, tile_y, bytes_per_row / 4)
 )