diff --git a/src/canvas.sh b/src/canvas.sh
index 6848b385..301fcfe4 100644
--- a/src/canvas.sh
+++ b/src/canvas.sh
@@ -655,7 +655,7 @@ function ble/canvas/trace/.process-csi-sequence {
       return ;;
     ([ABCDEFGIZ\`ade])
       local arg=0
-      [[ $param =~ ^[0-9]+$ ]] && arg=$param
+      [[ $param =~ ^[0-9]+$ ]] && ((arg=10#$param))
       ((arg==0&&(arg=1)))
 
       local x0=$x y0=$y
@@ -730,6 +730,7 @@ function ble/canvas/trace/.process-csi-sequence {
       # HVP "CSI f"
       local -a params
       ble/string#split-words params "${param//[^0-9]/ }"
+      params=("${params[@]/#/10#}")
       local x1 y1
       ((x1=params[1]-1))
       ((y1=params[0]-1))
diff --git a/src/decode.sh b/src/decode.sh
index e487dac4..bb3d84b4 100644
--- a/src/decode.sh
+++ b/src/decode.sh
@@ -560,19 +560,23 @@ function ble-decode-char/csi/.modify-key {
 function ble-decode-char/csi/.decode {
   local char=$1 rex key
   if ((char==126)); then
-    if rex='^27;([1-9][0-9]*);?([1-9][0-9]*)$' && [[ $_ble_decode_csi_args =~ $rex ]]; then
+    if rex='^>?27;([0-9]+);?([0-9]+)$' && [[ $_ble_decode_csi_args =~ $rex ]]; then
       # xterm "CSI 2 7 ; <mod> ; <char> ~" sequences
-      local key=$((BASH_REMATCH[2]&_ble_decode_MaskChar))
-      ble-decode-char/csi/.modify-key "${BASH_REMATCH[1]}"
+      local param1=$((10#${BASH_REMATCH[1]}))
+      local param2=$((10#${BASH_REMATCH[2]}))
+      local key=$((param2&_ble_decode_MaskChar))
+      ble-decode-char/csi/.modify-key "$param1"
       csistat=$key
       return
     fi
 
-    if rex='^([1-9][0-9]*)(;([1-9][0-9]*))?$' && [[ $_ble_decode_csi_args =~ $rex ]]; then
+    if rex='^>?([0-9]+)(;([0-9]+))?$' && [[ $_ble_decode_csi_args =~ $rex ]]; then
       # "CSI <key> ; <mod> ~" sequences
-      key=${_ble_decode_csimap_tilde[BASH_REMATCH[1]]}
+      local param1=$((10#${BASH_REMATCH[1]}))
+      local param3=$((10#${BASH_REMATCH[3]}))
+      key=${_ble_decode_csimap_tilde[param1]}
       if [[ $key ]]; then
-        ble-decode-char/csi/.modify-key "${BASH_REMATCH[3]}"
+        ble-decode-char/csi/.modify-key "$param3"
         csistat=$key
         return
       fi
@@ -583,20 +587,22 @@ function ble-decode-char/csi/.decode {
       # Note: 実は "CSI 1 ; mod u" が kp5 とする端末がある事に注意する。
       local rematch1=${BASH_REMATCH[1]}
       if [[ $rematch1 != 1 ]]; then
-        local key=$rematch1 mods=${BASH_REMATCH:${#rematch1}+1}
+        local key=$((10#$rematch1)) mods=$((10#${BASH_REMATCH:${#rematch1}+1}))
         ble-decode-char/csi/.modify-key "$mods"
         csistat=$key
       fi
       return
     fi
-  elif ((char==94||char==64)); then
-    if rex='^[1-9][0-9]*$' && [[ $_ble_decode_csi_args =~ $rex ]]; then
+  elif ((char==94||char==64)); then # ^, @
+    if rex='^[0-9]+$' && [[ $_ble_decode_csi_args =~ $rex ]]; then
       # rxvt "CSI <key> ^", "CSI <key> @" sequences
-      key=${_ble_decode_csimap_tilde[BASH_REMATCH[1]]}
+      local param1=$((10#${BASH_REMATCH[1]}))
+      local param3=$((10#${BASH_REMATCH[3]}))
+      key=${_ble_decode_csimap_tilde[param1]}
       if [[ $key ]]; then
         ((key|=_ble_decode_Ctrl,
           char==64&&(key|=_ble_decode_Shft)))
-        ble-decode-char/csi/.modify-key "${BASH_REMATCH[3]}"
+        ble-decode-char/csi/.modify-key "$param3"
         csistat=$key
         return
       fi
@@ -617,19 +623,22 @@ function ble-decode-char/csi/.decode {
     if rex='^([0-9]+);([0-9]+)$'; [[ $_ble_decode_csi_args =~ $rex ]]; then
       # DSR(6) に対する応答 CPR "CSI Pn ; Pn R"
       # Note: Poderosa は DSR(Pn;Pn) "CSI Pn ; Pn n" で返す。
-      ble/term/CPR/notify $((10#${BASH_REMATCH[1]})) $((10#${BASH_REMATCH[2]}))
+      local param1=$((10#${BASH_REMATCH[1]}))
+      local param2=$((10#${BASH_REMATCH[2]}))
+      ble/term/CPR/notify "$param1" "$param2"
       csistat=$_ble_decode_KCODE_IGNORE
-      return
+      return 0
     fi
   fi
 
   # pc-style "CSI 1; <mod> A" sequences
   key=${_ble_decode_csimap_alpha[char]}
   if [[ $key ]]; then
-    if rex='^(1?|1;([1-9][0-9]*))$' && [[ $_ble_decode_csi_args =~ $rex ]]; then
-      ble-decode-char/csi/.modify-key "${BASH_REMATCH[2]}"
+    if rex='^(1?|>?1;([0-9]+))$' && [[ $_ble_decode_csi_args =~ $rex ]]; then
+      local param2=$((10#${BASH_REMATCH[2]}))
+      ble-decode-char/csi/.modify-key "$param2"
       csistat=$key
-      return
+      return 0
     fi
   fi