diff --git a/src/seth/libexec/seth/seth-estimate b/src/seth/libexec/seth/seth-estimate
index 41864607e..26e03fd5e 100755
--- a/src/seth/libexec/seth/seth-estimate
+++ b/src/seth/libexec/seth/seth-estimate
@@ -4,6 +4,7 @@
 ###    or: seth estimate [<options>] <receiver> <data>
 ###    or: seth estimate [<options>] --create <code> <sig> [<args>]
 ###    or: seth estimate [<options>] --create <code> <data>
+###    or: seth estimate [<options>] --create <data>
 ###
 ### Perform a local call to <receiver> and return the gas usage.
 ###
@@ -15,7 +16,7 @@
 ### With `-F <sender>', simulate calling <receiver> from <sender>
 ### With `-V <value>', simulate transferring <value> to <receiver>.
 set -e
-[[ $2 ]] || seth --fail-usage "$0"
+[[ $1 ]] || seth --fail-usage "$0"
 
 if [[ $SETH_CREATE ]]; then
   DATA=$(seth --to-hexdata "$1")
diff --git a/src/seth/libexec/seth/seth-mktx b/src/seth/libexec/seth/seth-mktx
index b04c067c1..b9a340fdd 100755
--- a/src/seth/libexec/seth/seth-mktx
+++ b/src/seth/libexec/seth/seth-mktx
@@ -20,13 +20,11 @@ if [[ -z "$SETH_CREATE" ]]; then
 fi
 
 if [[ -z "$ETH_GAS" ]]; then
-  jshon+=(-n {})
-  [[ $TO ]] && jshon+=(-s "$TO" -i to)
-  jshon+=(-s "$data" -i data)
-  # shellcheck disable=SC2207
-  jshon+=($(SETH_PARAMS_NO_GAS=1 seth --send-params))
-  jshon+=(-i append)
-  ETH_GAS=$(seth rpc eth_estimateGas -- "${jshon[@]}")
+  if [[ $SETH_CREATE ]]; then
+    ETH_GAS=$(seth estimate --create $data)
+  else
+    ETH_GAS=$(seth estimate $TO $data)
+  fi
 fi
 
 args=(
diff --git a/src/seth/libexec/seth/seth-send b/src/seth/libexec/seth/seth-send
index ea1663b0f..3d72f1b5d 100755
--- a/src/seth/libexec/seth/seth-send
+++ b/src/seth/libexec/seth/seth-send
@@ -42,9 +42,18 @@ else
   fi
 fi
 
+if [[ -z "$ETH_GAS" ]]; then
+  if [[ $SETH_CREATE ]]; then
+    ETH_GAS=$(seth estimate --create $DATA)
+  else
+    ETH_GAS=$(seth estimate $TO ${DATA:-0x})
+  fi
+fi
+
 jshon+=(-n {})
 [[ $TO ]] && jshon+=(-s "$TO" -i to)
 [[ $DATA ]] && jshon+=(-s "$DATA" -i data)
+[[ $ETH_GAS ]] && jshon+=(-s "$ETH_GAS" -i gas)
 # shellcheck disable=SC2207
 jshon+=($(seth --send-params))
 jshon+=(-i append)