bison: both assigned number 52

I have got my DXF grammar down to the point where the only errors left
are things like
parser.y:4363.12-17: tokens '1032' and '1033' both assigned number 49
parser.y:3554.11-15: tokens '36' and '373' both assigned number 51
parser.y:3128.10-13: tokens '423' and '47' both assigned number 52
parser.y:3558.11-15: tokens '373' and '377' both assigned number 51
parser.y:3599.11-15: tokens '377' and '394' both assigned number 51
parser.y:427.14-17: tokens '-3' and '-1' both assigned number 45
parser.y:3432.11-15: tokens '221' and '292' both assigned number 50
parser.y:3535.11-15: tokens '394' and '366' both assigned number 51
parser.y:3482.11-15: tokens '366' and '321' both assigned number 51
parser.y:3218.10-13: tokens '78' and '71' both assigned number 55
parser.y:4367.12-17: tokens '1033' and '1040' both assigned number 49
parser.y:3090.10-13: tokens '292' and '26' both assigned number 50
parser.y:3385.11-15: tokens '26' and '230' both assigned number 50
parser.y:4336.12-17: tokens '1040' and '1011' both assigned number 49

how am I supposed to fix this? I can't find anything in the manuals
about this.

I am using bison.hairy.