diff --git a/lib/evmone/instructions.hpp b/lib/evmone/instructions.hpp
index 2d0f9c5f65..aa9f3fa3d6 100644
--- a/lib/evmone/instructions.hpp
+++ b/lib/evmone/instructions.hpp
@@ -822,17 +822,17 @@ inline void swap(StackTop stack) noexcept
 
 inline code_iterator dupn(StackTop stack, ExecutionState& state, code_iterator pos) noexcept
 {
-    const auto n = pos[1];
+    const auto n = pos[1] + 1;
 
     const auto stack_size = &stack.top() - state.stack_space.bottom();
 
-    if (stack_size <= n)
+    if (stack_size < n)
     {
         state.status = EVMC_STACK_UNDERFLOW;
         return nullptr;
     }
 
-    stack.push(stack[n]);
+    stack.push(stack[n - 1]);
 
     return pos + 2;
 }
diff --git a/lib/evmone/instructions_opcodes.hpp b/lib/evmone/instructions_opcodes.hpp
index ab28e73f59..8385c7120d 100644
--- a/lib/evmone/instructions_opcodes.hpp
+++ b/lib/evmone/instructions_opcodes.hpp
@@ -152,8 +152,8 @@ enum Opcode
     OP_LOG3 = 0xa3,
     OP_LOG4 = 0xa4,
 
-    OP_DUPN = 0xb3,
-    OP_SWAPN = 0xb4,
+    OP_DUPN = 0xb5,
+    OP_SWAPN = 0xb6,
 
     OP_CREATE = 0xf0,
     OP_CALL = 0xf1,
diff --git a/lib/evmone/instructions_xmacro.hpp b/lib/evmone/instructions_xmacro.hpp
index 7c830db6a9..d69b5c13f5 100644
--- a/lib/evmone/instructions_xmacro.hpp
+++ b/lib/evmone/instructions_xmacro.hpp
@@ -222,10 +222,10 @@
     ON_OPCODE_UNDEFINED(0xb0)                               \
     ON_OPCODE_UNDEFINED(0xb1)                               \
     ON_OPCODE_UNDEFINED(0xb2)                               \
+    ON_OPCODE_UNDEFINED(0xb3)                               \
+    ON_OPCODE_UNDEFINED(0xb4)                               \
     ON_OPCODE_IDENTIFIER(OP_DUPN, dupn)                     \
     ON_OPCODE_IDENTIFIER(OP_SWAPN, swapn)                   \
-    ON_OPCODE_UNDEFINED(0xb5)                               \
-    ON_OPCODE_UNDEFINED(0xb6)                               \
     ON_OPCODE_UNDEFINED(0xb7)                               \
     ON_OPCODE_UNDEFINED(0xb8)                               \
     ON_OPCODE_UNDEFINED(0xb9)                               \
diff --git a/test/unittests/eof_validation_test.cpp b/test/unittests/eof_validation_test.cpp
index 1c87956ce9..1124eaba8b 100644
--- a/test/unittests/eof_validation_test.cpp
+++ b/test/unittests/eof_validation_test.cpp
@@ -219,7 +219,8 @@ TEST(eof_validation, EOF1_terminating_instructions)
     {
         const auto& op_traits = traits[opcode];
         // Skip undefined opcodes.
-        if (op_traits.name == nullptr)
+        // TODO iterate for all EOF revisions
+        if (op_traits.name == nullptr || op_traits.since == EVMC_CANCUN)
             continue;
 
         bytes code{static_cast<uint8_t>(opcode) + bytes(op_traits.immediate_size, 0)};
@@ -230,6 +231,6 @@ TEST(eof_validation, EOF1_terminating_instructions)
                                    opcode == OP_INVALID || opcode == OP_SELFDESTRUCT) ?
                                    EOFValidationError::success :
                                    EOFValidationError::missing_terminating_instruction);
-        EXPECT_EQ(validate_eof(container, EVMC_CANCUN), expected) << hex(code);
+        EXPECT_EQ(validate_eof(container), expected) << hex(code);
     }
 }
diff --git a/test/unittests/evm_test.cpp b/test/unittests/evm_test.cpp
index f351c552cc..14a585ea02 100644
--- a/test/unittests/evm_test.cpp
+++ b/test/unittests/evm_test.cpp
@@ -197,14 +197,26 @@ TEST_P(evm, swapn)
     EXPECT_STATUS(EVMC_SUCCESS);
     EXPECT_OUTPUT_INT(19);
 
+    execute(pushes + OP_SWAPN + "00" + OP_DUPN + "01" + ret_top());
+    EXPECT_STATUS(EVMC_SUCCESS);
+    EXPECT_OUTPUT_INT(20);
+
     execute(pushes + OP_SWAPN + "01" + ret_top());
     EXPECT_STATUS(EVMC_SUCCESS);
     EXPECT_OUTPUT_INT(18);
 
+    execute(pushes + OP_SWAPN + "01" + OP_DUPN + "02" + ret_top());
+    EXPECT_STATUS(EVMC_SUCCESS);
+    EXPECT_OUTPUT_INT(20);
+
     execute(pushes + OP_SWAPN + "12" + ret_top());
     EXPECT_STATUS(EVMC_SUCCESS);
     EXPECT_OUTPUT_INT(1);
 
+    execute(pushes + OP_SWAPN + "12" + OP_DUPN + "13" + ret_top());
+    EXPECT_STATUS(EVMC_SUCCESS);
+    EXPECT_OUTPUT_INT(20);
+
     execute(pushes + OP_SWAPN + "13" + ret_top());
     EXPECT_STATUS(EVMC_STACK_UNDERFLOW);
 }
diff --git a/test/unittests/instructions_test.cpp b/test/unittests/instructions_test.cpp
index 2d44f940e6..e86550724b 100644
--- a/test/unittests/instructions_test.cpp
+++ b/test/unittests/instructions_test.cpp
@@ -136,9 +136,9 @@ TEST(instructions, compare_undefined_instructions)
 
         for (size_t i = 0; i < instr_tbl.size(); ++i)
         {
-            // Skip DUPN and SWAPN for Cancun. They are not defined in evmc
+            // Skip DUPN and SWAPN. They are not defined in evmc
             // TODO: Define DUPN and SWAPN in evmc
-            if (r == EVMC_CANCUN && (Opcode(i) == OP_DUPN || Opcode(i) == OP_SWAPN))
+            if (Opcode(i) == OP_DUPN || Opcode(i) == OP_SWAPN)
                 continue;
             EXPECT_EQ(instr_tbl[i] == instr::undefined, evmc_names_tbl[i] == nullptr) << i;
         }
@@ -150,10 +150,9 @@ TEST(instructions, compare_with_evmc_instruction_names)
     const auto* evmc_tbl = evmc_get_instruction_names_table(EVMC_MAX_REVISION);
     for (size_t i = 0; i < instr::traits.size(); ++i)
     {
-        // Skip DUPN and SWAPN for Cancun. They are not defined in evmc
+        // Skip DUPN and SWAPN. They are not defined in evmc
         // TODO: Define DUPN and SWAPN in evmc
-        if (instr::traits[i].since == EVMC_CANCUN &&
-            (Opcode(i) == OP_DUPN || Opcode(i) == OP_SWAPN))
+        if (Opcode(i) == OP_DUPN || Opcode(i) == OP_SWAPN)
             continue;
         EXPECT_STREQ(instr::traits[i].name, evmc_tbl[i]);
     }