diff --git a/src/common/func.c b/src/common/func.c
index ff17f26..11653f0 100644
--- a/src/common/func.c
+++ b/src/common/func.c
@@ -1220,7 +1220,7 @@ static Token region_macro(RegFuncInit init, RegFuncUpdt updt, RegFuncFinl finl,
   // Evaluate over all cells in block defined by locations l1 and l2
   int x1 = l1[X], x2 = l2[X]; posorder(&x1, &x2);
   int y1 = l1[Y], y2 = l2[Y]; posorder(&y1, &y2);
-  int z1 = l1[Y], z2 = l2[Z]; posorder(&z1, &z2);
+  int z1 = l1[Z], z2 = l2[Z]; posorder(&z1, &z2);
   Location l; l[X] = x1; l[Y] = y1; l[Z] = z1;
   Token t;
   if (argc == 3) {