diff --git a/src/script/interpreter.cpp b/src/script/interpreter.cpp
index e78c86731d..dbac2335f9 100644
--- a/src/script/interpreter.cpp
+++ b/src/script/interpreter.cpp
@@ -815,6 +815,7 @@ bool EvalScript(std::vector<std::vector<unsigned char> >& stack, const CScript&
                 break;
 
                 case OP_SUBSTR:
+                case OP_SUBSTR_LAZY:
                 {
                     if (stack.size() < 3)
                         return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
@@ -823,6 +824,30 @@ bool EvalScript(std::vector<std::vector<unsigned char> >& stack, const CScript&
                     CScriptNum start(stacktop(-2), fRequireMinimal);
                     CScriptNum length(stacktop(-1), fRequireMinimal);
 
+                    if (opcode == OP_SUBSTR_LAZY) {
+                        if (start < 0)
+                            start = 0;
+
+                        if (length < 0)
+                            length = 0;
+
+                        if (start >= vch1.size()) {
+                            popstack(stack);
+                            popstack(stack);
+                            popstack(stack);
+                            stack.push_back(vchZero);
+                            break;
+                        }
+
+                        if (length > MAX_SCRIPT_ELEMENT_SIZE)
+                            length = MAX_SCRIPT_ELEMENT_SIZE;
+
+                        // start + length cannot overflow because of the restrictions immediately abo
+                        if (start + length > vch1.size()) {
+                            length = CScriptNum(vch1.size()) - start;
+                        }
+                    }
+
                     if (length < 0 || start < 0)
                         return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
 
diff --git a/src/script/script.cpp b/src/script/script.cpp
index 532860fe18..b27f4eaa89 100644
--- a/src/script/script.cpp
+++ b/src/script/script.cpp
@@ -72,6 +72,7 @@ const char* GetOpName(opcodetype opcode)
     // splice ops
     case OP_CAT                    : return "OP_CAT";
     case OP_SUBSTR                 : return "OP_SUBSTR";
+    case OP_SUBSTR_LAZY            : return "OP_SUBSTR_LAZY";
     case OP_LEFT                   : return "OP_LEFT";
     case OP_RIGHT                  : return "OP_RIGHT";
     case OP_SIZE                   : return "OP_SIZE";
diff --git a/src/script/script.h b/src/script/script.h
index e811bab302..5fbbb891b6 100644
--- a/src/script/script.h
+++ b/src/script/script.h
@@ -116,6 +116,7 @@ enum opcodetype
     // splice ops
     OP_CAT = 0x7e,
     OP_SUBSTR = 0x7f,
+    OP_SUBSTR_LAZY = 0xc3,
     OP_LEFT = 0x80,
     OP_RIGHT = 0x81,
     OP_SIZE = 0x82,
@@ -195,7 +196,7 @@ enum opcodetype
 };
 
 // Maximum value that an opcode can be
-static const unsigned int MAX_OPCODE = OP_CHECKSIGFROMSTACKVERIFY;
+static const unsigned int MAX_OPCODE = OP_SUBSTR_LAZY; // 0xc3
 
 const char* GetOpName(opcodetype opcode);
 
diff --git a/src/test/data/script_tests.json b/src/test/data/script_tests.json
index 359b5e613f..8e0da29cfa 100644
--- a/src/test/data/script_tests.json
+++ b/src/test/data/script_tests.json
@@ -876,7 +876,6 @@
 ["1", "IF 0xbd ELSE 1 ENDIF", "P2SH,STRICTENC", "BAD_OPCODE"],
 ["1", "IF 0xbe ELSE 1 ENDIF", "P2SH,STRICTENC", "BAD_OPCODE"],
 ["1", "IF 0xbf ELSE 1 ENDIF", "P2SH,STRICTENC", "BAD_OPCODE"],
-["1", "IF 0xc3 ELSE 1 ENDIF", "P2SH,STRICTENC", "BAD_OPCODE"],
 ["1", "IF 0xc4 ELSE 1 ENDIF", "P2SH,STRICTENC", "BAD_OPCODE"],
 ["1", "IF 0xc5 ELSE 1 ENDIF", "P2SH,STRICTENC", "BAD_OPCODE"],
 ["1", "IF 0xc6 ELSE 1 ENDIF", "P2SH,STRICTENC", "BAD_OPCODE"],
diff --git a/src/test/script_tests.cpp b/src/test/script_tests.cpp
index 0c23b7a353..33dc6054eb 100644
--- a/src/test/script_tests.cpp
+++ b/src/test/script_tests.cpp
@@ -1474,7 +1474,7 @@ BOOST_AUTO_TEST_CASE(script_HasValidOps)
     BOOST_CHECK(script.HasValidOps());
     script = ScriptFromHex("ff88ac"); // Script with OP_INVALIDOPCODE explicit
     BOOST_CHECK(!script.HasValidOps());
-    script = ScriptFromHex("88acc3"); // Script with undefined opcode: one higher then MAX_OPCODE
+    script = ScriptFromHex("88acc4"); // Script with undefined opcode: one higher then MAX_OPCODE
     BOOST_CHECK(!script.HasValidOps());
 }