diff --git a/av1/encoder/encodeframe.c b/av1/encoder/encodeframe.c
index 773e368..3f93d53 100644
--- a/av1/encoder/encodeframe.c
+++ b/av1/encoder/encodeframe.c
@@ -4447,7 +4447,9 @@
     best_param = curr_param;
     for (i = 0; i < n_refinements; i++) {
       // look to the left
-      *param = curr_param - step;
+      *param =
+          (int16_t)clamp(curr_param - step, p < 2 ? GM_TRANS_MIN : GM_ALPHA_MIN,
+                         p < 2 ? GM_TRANS_MAX : GM_ALPHA_MAX);
       step_error =
           av1_warp_erroradv(wm,
 #if CONFIG_AOM_HIGHBITDEPTH
@@ -4464,7 +4466,9 @@
       }
 
       // look to the right
-      *param = curr_param + step;
+      *param =
+          (int16_t)clamp(curr_param + step, p < 2 ? GM_TRANS_MIN : GM_ALPHA_MIN,
+                         p < 2 ? GM_TRANS_MAX : GM_ALPHA_MAX);
       step_error =
           av1_warp_erroradv(wm,
 #if CONFIG_AOM_HIGHBITDEPTH
diff --git a/av1/encoder/rdopt.c b/av1/encoder/rdopt.c
index 6f4a0d7..fef5901 100644
--- a/av1/encoder/rdopt.c
+++ b/av1/encoder/rdopt.c
@@ -4137,7 +4137,7 @@
     bits =
         (gm->motion_params.wmmat[0].as_int ? ((GM_ABS_TRANS_BITS + 1) * 2) : 0);
   }
-  return (bits << AV1_PROB_COST_SHIFT) + gmtype_cost[gm->gmtype];
+  return bits ? (bits << AV1_PROB_COST_SHIFT) + gmtype_cost[gm->gmtype] : 0;
 }
 
 #define GLOBAL_MOTION_RATE(ref)                            \