diff --git a/KPP/fullchem/gckpp_Integrator.F90 b/KPP/fullchem/gckpp_Integrator.F90
index 0a0d9b9bf..ed8a5c952 100644
--- a/KPP/fullchem/gckpp_Integrator.F90
+++ b/KPP/fullchem/gckpp_Integrator.F90
@@ -430,7 +430,7 @@ SUBROUTINE Rosenbrock(N,Y,Tstart,Tend, &
     ENDIF
 !~~~> Auto-reduction threshold ratio (only if ICNTRL(10) is not zero)
     AR_thr_ratio = 0.001_dp
-    IF (RCNTRL(8) > ZERO) THEN
+    IF (RCNTRL(10) > ZERO) THEN
        AR_thr_ratio = RCNTRL(10)
     ENDIF
 !~~~>  CALL Auto-reducing Rosenbrock method