diff --git a/compiler/characterizer/delay.py b/compiler/characterizer/delay.py
index 89bf3be6..d737d2c9 100644
--- a/compiler/characterizer/delay.py
+++ b/compiler/characterizer/delay.py
@@ -345,20 +345,19 @@ class delay():
 
             target_period = 0.5 * (ub_period + lb_period)
             debug.info(1, "MinPeriod Search: {0}ns (ub: {1} lb: {2})".format(target_period,
-                                                                                                       ub_period,
-                                                                                                       lb_period))
+                                                                             ub_period,
+                                                                             lb_period))
 
             (success, delay_out) = self.try_period(feasible_period, target_period, data_value)
             if success:
-                if ch.relative_compare(ub_period, target_period):
-                    # use the two values to compare, but only return the ub since it is guaranteed feasible
-                    (success, delay_out) = self.try_period(feasible_period, ub_period, data_value)
-                    return (ub_period, delay_out)
-                fail_flag = False
                 ub_period = target_period
             else:
                 lb_period = target_period
 
+            if ch.relative_compare(ub_period, lb_period):
+                # use the two values to compare, but only return the ub since it is guaranteed feasible
+                (success, delay_out) = self.try_period(feasible_period, ub_period, data_value)
+                return (ub_period, delay_out)
 
         self.error("Should not reach here.",-1)
         return (target_period, delay_out)