diff --git a/docs/archapi.md b/docs/archapi.md
index 9ecb1bf1..55f5c3bc 100644
--- a/docs/archapi.md
+++ b/docs/archapi.md
@@ -236,7 +236,7 @@ Return the type (input/output/inout) of the given bel pin.
 
 Return a list of all pins on that bel.
 
-### CellBelPinRangeT getBelPinsForCellPin(CellInfo *cell_info, IdString pin) const
+### CellBelPinRangeT getBelPinsForCellPin(const CellInfo *cell_info, IdString pin) const
 
 Return the list of bel pin names that a given cell pin should be routed to. In most cases there will be a single bel pin for each cell pin; and output pins must _always_ have only one bel pin associated with them.