diff --git a/bedstead.c b/bedstead.c
index f206380..5604a82 100644
--- a/bedstead.c
+++ b/bedstead.c
@@ -1090,6 +1090,8 @@ static struct glyph {
  {{037,000,004,004,037,004,004,000,000}, 0x2213 }, /* minusplus */
  {{000,000,004,016,004,000,000,000,000}, 0x2219 }, /* bulletoperator */
  {{007,004,004,004,024,014,004,000,000}, 0x221a, "radical" },
+ {{023,012,022,012,022,006,002,000,000}, 0x221b }, /* cube root */
+ {{015,025,035,005,001,003,001,000,000}, 0x221c }, /* fourth root */
  {{000,012,025,025,025,012,000,000,000}, 0x221e, "infinity" },
  {{000,020,020,020,020,037,000,000,000}, 0x221f, "orthogonal" },
  {{004,004,004,004,004,004,004,000,000}, 0x2223, }, /* divides */