diff --git a/cmd/ethtest/main.go b/cmd/ethtest/main.go
index 94ab779db..96ef94e40 100644
--- a/cmd/ethtest/main.go
+++ b/cmd/ethtest/main.go
@@ -95,10 +95,15 @@ func RunVmTest(js string) (failed int) {
 			failed = 1
 		}
 
-		gexp := ethutil.Big(test.Gas)
-		if gexp.Cmp(gas) != 0 {
-			log.Printf("%s's gas failed. Expected %v, got %v\n", name, gexp, gas)
+		if len(test.Gas) == 0 && err == nil {
+			log.Printf("0 gas indicates error but no error given by VM")
 			failed = 1
+		} else {
+			gexp := ethutil.Big(test.Gas)
+			if gexp.Cmp(gas) != 0 {
+				log.Printf("%s's gas failed. Expected %v, got %v\n", name, gexp, gas)
+				failed = 1
+			}
 		}
 
 		for addr, account := range test.Post {
diff --git a/tests/files/VMTests/RandomTests/randomTest.json b/tests/files/VMTests/RandomTests/randomTest.json
deleted file mode 100644
index dad2ee4a2..000000000
--- a/tests/files/VMTests/RandomTests/randomTest.json
+++ /dev/null
@@ -1,46 +0,0 @@
-{
-    "randomVMtest" : {
-        "callcreates" : [
-        ],
-        "env" : {
-            "currentCoinbase" : "2adc25665018aa1fe0e6bc666dac8fc2697ff9ba",
-            "currentDifficulty" : "256",
-            "currentGasLimit" : "1000000",
-            "currentNumber" : "0",
-            "currentTimestamp" : "1",
-            "previousHash" : "5e20a0453cecd065ea59c37ac63e079ee08998b6045136a8ce6635c7912ec0b6"
-        },
-        "exec" : {
-            "address" : "0f572e5295c57f15886f9b263e2f6d2d6c7b5ec6",
-            "caller" : "cd1722f3947def4cf144679da39c4c32bdc35681",
-            "code" : "0x675545",
-            "data" : "0x",
-            "gas" : "10000",
-            "gasPrice" : "100000000000000",
-            "origin" : "cd1722f3947def4cf144679da39c4c32bdc35681",
-            "value" : "1000000000000000000"
-        },
-        "gas" : "9999",
-        "logs" : [
-        ],
-        "out" : "0x",
-        "post" : {
-            "0f572e5295c57f15886f9b263e2f6d2d6c7b5ec6" : {
-                "balance" : "1000000000000000000",
-                "code" : "0x675545",
-                "nonce" : "0",
-                "storage" : {
-                }
-            }
-        },
-        "pre" : {
-            "0f572e5295c57f15886f9b263e2f6d2d6c7b5ec6" : {
-                "balance" : "1000000000000000000",
-                "code" : "0x675545",
-                "nonce" : "0",
-                "storage" : {
-                }
-            }
-        }
-    }
-}
\ No newline at end of file
diff --git a/vm/vm_debug.go b/vm/vm_debug.go
index 9a538c940..933fb7b12 100644
--- a/vm/vm_debug.go
+++ b/vm/vm_debug.go
@@ -140,7 +140,7 @@ func (self *DebugVm) Run(me, caller ClosureRef, code []byte, value, gas, price *
 		// Stack checks only
 		case ISZERO, CALLDATALOAD, POP, JUMP, NOT: // 1
 			require(1)
-		case ADD, SUB, DIV, SDIV, MOD, SMOD, LT, GT, SLT, SGT, EQ, AND, OR, XOR, BYTE: // 2
+		case ADD, SUB, DIV, SDIV, MOD, SMOD, LT, GT, SLT, SGT, EQ, AND, OR, XOR, BYTE, SIGNEXTEND: // 2
 			require(2)
 		case ADDMOD, MULMOD: // 3
 			require(3)