diff --git a/input/thermo/groups/radical.py b/input/thermo/groups/radical.py
index a1ea1f3701..d6526e7fe2 100644
--- a/input/thermo/groups/radical.py
+++ b/input/thermo/groups/radical.py
@@ -8314,8 +8314,8 @@
     label = "CO",
     group = 
 """
-1 * Ct   u0 p1 c-1 {2,T}
-2   O4tc u0 p1 c+1 {1,T}
+1 * CO  u0 p1 {2,D}
+2   O2d u0 p2 {1,D}
 """,
     thermo = ThermoData(
         Tdata = ([300,400,500,600,800,1000,1500],'K'),
@@ -9009,7 +9009,7 @@
                 L5: CsJ2_S_singlet
             L4: CdJ2_singlet
                 L5: CCdJ2_singlet
-            L4: CO
+                L5: CO
             L4: CdJ2-Sd_singlet
         L3: Oa_singlet
         L3: SiJ2_singlet