diff --git a/libevm/VM.cpp b/libevm/VM.cpp
index e0b487c9b..19339ce49 100644
--- a/libevm/VM.cpp
+++ b/libevm/VM.cpp
@@ -341,8 +341,12 @@ bytesConstRef VM::go(ExtVMFace& _ext, OnOpFunc const& _onOp, uint64_t _steps)
 			break;
 		case Instruction::CALLDATALOAD:
 		{
-			if ((unsigned)m_stack.back() + (uint64_t)31 < _ext.data.size())
-				m_stack.back() = (u256)*(h256 const*)(_ext.data.data() + (unsigned)m_stack.back());
+			if ((bigint)m_stack.back() + 31 < _ext.data.size())
+				m_stack.back() = (u256)*(h256 const*)(_ext.data.data() + (size_t)m_stack.back());
+			else if ((bigint)m_stack.back() >= _ext.data.size())
+			{
+				m_stack.back() = u256();
+			}
 			else
 			{
 				h256 r;
diff --git a/test/vmEnvironmentalInfoTestFiller.json b/test/vmEnvironmentalInfoTestFiller.json
index d9e1ef654..951e65c32 100644
--- a/test/vmEnvironmentalInfoTestFiller.json
+++ b/test/vmEnvironmentalInfoTestFiller.json
@@ -367,6 +367,34 @@
         }
     },
 
+    "calldataload_BigOffset": {
+        "env" : {
+            "previousHash" : "5e20a0453cecd065ea59c37ac63e079ee08998b6045136a8ce6635c7912ec0b6",
+            "currentNumber" : "0",
+            "currentGasLimit" : "1000000",
+            "currentDifficulty" : "256",
+            "currentTimestamp" : "1",
+            "currentCoinbase" : "2adc25665018aa1fe0e6bc666dac8fc2697ff9ba"
+        },
+        "pre" : {
+            "0f572e5295c57f15886f9b263e2f6d2d6c7b5ec6" : {
+                "balance" : "100000000000000000000000",
+                "nonce" : "0",
+                "code" : "{ [[ 0 ]] (CALLDATALOAD 0x4200000000000000000000000000000000000000000000000000000000000000)}",
+                "storage": {}
+            }
+        },
+        "exec" : {
+            "address" : "0f572e5295c57f15886f9b263e2f6d2d6c7b5ec6",
+            "origin" : "cd1722f3947def4cf144679da39c4c32bdc35681",
+            "caller" : "cd1722f3947def4cf144679da39c4c32bdc35681",
+            "value" : "1000000000000000000",
+            "data" : "0x4200000000000000000000000000000000000000000000000000000000000000",
+            "gasPrice" : "1000000000",
+            "gas" : "100000000000"
+        }
+    },
+
     "calldataload1": {
         "env" : {
             "previousHash" : "5e20a0453cecd065ea59c37ac63e079ee08998b6045136a8ce6635c7912ec0b6",