diff --git a/lib/vm/opFns.js b/lib/vm/opFns.js
index 41ef8a1349..30171fd733 100644
--- a/lib/vm/opFns.js
+++ b/lib/vm/opFns.js
@@ -259,7 +259,7 @@ module.exports = {
     subMemUsage(runState, memOffset, dataLength)
     subGas(runState, new BN(runState._common.param('gasPrices', 'copy')).imul(dataLength.divCeil(new BN(32))))
 
-    const data = getDataSlice(dataOffset, dataLength, runState.callData)
+    const data = getDataSlice(runState.callData, dataOffset, dataLength)
     memOffset = memOffset.toNumber()
     dataLength = dataLength.toNumber()
     runState.memory.extend(memOffset, dataLength)
@@ -272,7 +272,7 @@ module.exports = {
     subMemUsage(runState, memOffset, length)
     subGas(runState, new BN(runState._common.param('gasPrices', 'copy')).imul(length.divCeil(new BN(32))))
 
-    const data = getDataSlice(codeOffset, length, runState.code)
+    const data = getDataSlice(runState.code, codeOffset, length)
     memOffset = memOffset.toNumber()
     length = length.toNumber()
     runState.memory.extend(memOffset, length)
@@ -297,7 +297,7 @@ module.exports = {
 
     stateManager.getContractCode(address, function (err, code) {
       if (err) return cb(err)
-      const data = getDataSlice(codeOffset, length, code)
+      const data = getDataSlice(code, codeOffset, length)
       memOffset = memOffset.toNumber()
       length = length.toNumber()
       runState.memory.extend(memOffset, length)
@@ -341,7 +341,7 @@ module.exports = {
     subMemUsage(runState, memOffset, length)
     subGas(runState, new BN(runState._common.param('gasPrices', 'copy')).mul(length.divCeil(new BN(32))))
 
-    const data = getDataSlice(returnDataOffset, length, utils.toBuffer(runState.lastReturned))
+    const data = getDataSlice(utils.toBuffer(runState.lastReturned), returnDataOffset, length)
     memOffset = memOffset.toNumber()
     length = length.toNumber()
     runState.memory.extend(memOffset, length)
@@ -948,7 +948,7 @@ function subMemUsage (runState, offset, length) {
  * @param {BN} length
  * @param {Buffer} data
  */
-function getDataSlice (offset, length, data) {
+function getDataSlice (data, offset, length) {
   let len = new BN(data.length)
   if (offset.gt(len)) {
     offset = len
@@ -1041,7 +1041,7 @@ function makeCall (runState, callOptions, localOpts, cb) {
     // save results to memory
     if (results.vm.return && (!results.vm.exceptionError || results.vm.exceptionError.error === ERROR.REVERT)) {
       if (results.vm.return.length > 0) {
-        const data = getDataSlice(new BN(0), localOpts.outLength, results.vm.return)
+        const data = getDataSlice(results.vm.return, new BN(0), localOpts.outLength)
         const memOffset = localOpts.outOffset.toNumber()
         const dataLength = localOpts.outLength.toNumber()
         runState.memory.extend(memOffset, dataLength)