diff --git a/src/ptp/rtl/taxi_ptp_td_leaf.sv b/src/ptp/rtl/taxi_ptp_td_leaf.sv
index 4bb6f25..8ea373b 100644
--- a/src/ptp/rtl/taxi_ptp_td_leaf.sv
+++ b/src/ptp/rtl/taxi_ptp_td_leaf.sv
@@ -420,7 +420,7 @@ always_comb begin
         endcase
 
         // time integral of error
-        case (dst_gain_sel_reg)
+        case (dst_gain_sel_reg && !dst_sync_locked_reg)
             1'd0: {dst_ovf, dst_err_int_next} = $signed({1'b0, dst_err_int_reg}) + (PHASE_ACC_W+2)'($signed(sample_acc_sync_reg));
             1'd1: {dst_ovf, dst_err_int_next} = $signed({1'b0, dst_err_int_reg}) + (PHASE_ACC_W+2)'($signed(sample_acc_sync_reg) * 2**7);
         endcase
@@ -435,7 +435,7 @@ always_comb begin
         end
 
         // compute output
-        case (dst_gain_sel_reg)
+        case (dst_gain_sel_reg && !dst_sync_locked_reg)
             1'd0: {dst_ovf, dst_phase_inc_next} = $signed({1'b0, dst_err_int_reg}) + ($signed(sample_acc_sync_reg) * 2**4);
             1'd1: {dst_ovf, dst_phase_inc_next} = $signed({1'b0, dst_err_int_reg}) + ($signed(sample_acc_sync_reg) * 2**11);
         endcase