diff --git a/core/vm/contracts.go b/core/vm/contracts.go
index cae0be9f2de..03cf5d25b73 100644
--- a/core/vm/contracts.go
+++ b/core/vm/contracts.go
@@ -591,8 +591,11 @@ func (c *bigModExp) RequiredGas(input []byte) uint64 {
 		if expLen > 32 {
 			expHead.SetBytes(getData(input, baseLen, 32))
 		} else {
-			// TODO: Check that if expLen < baseLen, then getData will return an empty slice
-			expHead.SetBytes(getData(input, baseLen, expLen))
+			if expLen < baseLen && uint64(len(input)) < baseLen+expLen {
+				expHead.SetBytes([]byte{})
+			} else {
+				expHead.SetBytes(getData(input, baseLen, expLen))
+			}
 		}
 	}