diff --git a/cli/nep_test/nep17_test.go b/cli/nep_test/nep17_test.go
index 081780928..6aeed8df7 100644
--- a/cli/nep_test/nep17_test.go
+++ b/cli/nep_test/nep17_test.go
@@ -99,7 +99,7 @@ func TestNEP17Balance(t *testing.T) {
 		}
 
 		e.CheckNextLine(t, "^\\s*$")
-		addr4, err := address.StringToUint160("NQ3nAdFQXzemHC9uvr4af2Ysap6aZJpqgN") // deployed verify.go contract
+		addr4, err := address.StringToUint160("NfWu6j9KPLQMsWLfHz9iZRy5sNw2bUZWQL") // deployed verify.go contract
 		require.NoError(t, err)
 		e.CheckNextLine(t, "^Account "+address.Uint160ToString(addr4))
 		e.CheckEOF(t)
diff --git a/cli/testdata/wallet1_solo.json b/cli/testdata/wallet1_solo.json
index d71a06198..4c9345ae1 100644
--- a/cli/testdata/wallet1_solo.json
+++ b/cli/testdata/wallet1_solo.json
@@ -61,11 +61,10 @@
       "isDefault": false
     },
     {
-      "address": "NQ3nAdFQXzemHC9uvr4af2Ysap6aZJpqgN",
+      "address": "NfWu6j9KPLQMsWLfHz9iZRy5sNw2bUZWQL",
       "key": "6PYSATFztBa3CHjSR6sLAKungUEAbQUCVE16KzmaQQ38gLeYGZ9Knd5mGv",
       "label": "verify",
       "contract": {
-        "script": "EdsgQFcAA0BXAQR4eXp7VBTAcAwOT25ORVAxMVBheW1lbnRoUEGVAW9hIUA=",
         "parameters": [],
         "deployed": true
       },
diff --git a/cli/vm/cli_test.go b/cli/vm/cli_test.go
index 4552f9253..724e2d118 100644
--- a/cli/vm/cli_test.go
+++ b/cli/vm/cli_test.go
@@ -914,7 +914,7 @@ func TestRunWithHistoricState(t *testing.T) {
 	e.checkNextLine(t, "READY: loaded 36 instructions")
 	e.checkStack(t, []byte{1})
 	e.checkNextLine(t, "READY: loaded 36 instructions")
-	e.checkNextLineExact(t, "Error: at instruction 31 (SYSCALL): failed to invoke syscall 1381727586: called contract a00e3c2643a08a452d8b0bdd31849ae11a17c445 not found: key not found\n")
+	e.checkNextLineExact(t, "Error: at instruction 31 (SYSCALL): failed to invoke syscall 1381727586: called contract cd583ac7a1a4faef70d6e9f513bc988dde22f672 not found: key not found\n")
 }
 
 func TestEvents(t *testing.T) {
@@ -939,7 +939,7 @@ func TestEvents(t *testing.T) {
 			}),
 		}),
 	}
-	e.checkNextLine(t, "READY: loaded 44 instructions")
+	e.checkNextLine(t, "READY: loaded 43 instructions")
 	e.checkStack(t, stackitem.Null{})
 	e.checkEvents(t, true, expectedEvent)  // automatically printed after `run` command
 	e.checkEvents(t, false, expectedEvent) // printed after `events` command
diff --git a/pkg/compiler/codegen.go b/pkg/compiler/codegen.go
index 871433851..f21d421c4 100644
--- a/pkg/compiler/codegen.go
+++ b/pkg/compiler/codegen.go
@@ -1945,10 +1945,16 @@ func transformArgs(fs *funcScope, fun ast.Expr, isBuiltin bool, args []ast.Expr)
 
 // emitConvert converts the top stack item to the specified type.
 func (c *codegen) emitConvert(typ stackitem.Type) {
-	emit.Opcodes(c.prog.BinWriter, opcode.DUP)
-	emit.Instruction(c.prog.BinWriter, opcode.ISTYPE, []byte{byte(typ)})
-	emit.Instruction(c.prog.BinWriter, opcode.JMPIF, []byte{2 + 2}) // After CONVERT.
-	emit.Instruction(c.prog.BinWriter, opcode.CONVERT, []byte{byte(typ)})
+	if typ == stackitem.BooleanT {
+		// DUP + ISTYPE + JMPIF costs 3 already with CONVERT of a cost 8192.
+		// NOT+NOT at the same time costs 4 and always works (and is shorter).
+		emit.Opcodes(c.prog.BinWriter, opcode.NOT, opcode.NOT)
+	} else {
+		emit.Opcodes(c.prog.BinWriter, opcode.DUP)
+		emit.Instruction(c.prog.BinWriter, opcode.ISTYPE, []byte{byte(typ)})
+		emit.Instruction(c.prog.BinWriter, opcode.JMPIF, []byte{2 + 2}) // After CONVERT.
+		emit.Instruction(c.prog.BinWriter, opcode.CONVERT, []byte{byte(typ)})
+	}
 }
 
 func (c *codegen) convertByteArray(elems []ast.Expr) {
diff --git a/pkg/services/rpcsrv/server_test.go b/pkg/services/rpcsrv/server_test.go
index 93f015121..d61629d51 100644
--- a/pkg/services/rpcsrv/server_test.go
+++ b/pkg/services/rpcsrv/server_test.go
@@ -2557,7 +2557,7 @@ func testRPCProtocol(t *testing.T, doRPCCall func(string, string, *testing.T) []
 		t.Run("contract-based verification with parameters", func(t *testing.T) {
 			verAcc, err := util.Uint160DecodeStringLE(verifyWithArgsContractHash)
 			require.NoError(t, err)
-			checkContract(t, verAcc, []byte{}, 737530) // No C# match, but we believe it's OK and it differs from the one above.
+			checkContract(t, verAcc, []byte{}, 490890) // No C# match, but we believe it's OK and it differs from the one above.
 		})
 		t.Run("contract-based verification with invocation script", func(t *testing.T) {
 			verAcc, err := util.Uint160DecodeStringLE(verifyWithArgsContractHash)
@@ -2567,7 +2567,7 @@ func testRPCProtocol(t *testing.T, doRPCCall func(string, string, *testing.T) []
 			emit.Int(invocWriter.BinWriter, 5)
 			emit.String(invocWriter.BinWriter, "")
 			invocScript := invocWriter.Bytes()
-			checkContract(t, verAcc, invocScript, 640360) // No C# match, but we believe it's OK and it has a specific invocation script overriding anything server-side.
+			checkContract(t, verAcc, invocScript, 393720) // No C# match, but we believe it's OK and it has a specific invocation script overriding anything server-side.
 		})
 	})
 }
diff --git a/pkg/smartcontract/param_type_test.go b/pkg/smartcontract/param_type_test.go
index af643b042..83294a316 100644
--- a/pkg/smartcontract/param_type_test.go
+++ b/pkg/smartcontract/param_type_test.go
@@ -347,7 +347,7 @@ func TestEncodeDefaultValue(t *testing.T) {
 	for p, l := range map[ParamType]int{
 		UnknownType:          0,
 		AnyType:              66,
-		BoolType:             3,
+		BoolType:             2,
 		IntegerType:          33,
 		ByteArrayType:        66,
 		StringType:           66,
diff --git a/pkg/vm/emit/emit.go b/pkg/vm/emit/emit.go
index 6ce7fa0ac..fedf8929d 100644
--- a/pkg/vm/emit/emit.go
+++ b/pkg/vm/emit/emit.go
@@ -31,12 +31,11 @@ func Opcodes(w *io.BinWriter, ops ...opcode.Opcode) {
 
 // Bool emits a bool type to the given buffer.
 func Bool(w *io.BinWriter, ok bool) {
-	if ok {
-		Opcodes(w, opcode.PUSHT)
-	} else {
-		Opcodes(w, opcode.PUSHF)
+	var opVal = opcode.PUSHF
+	if !ok {
+		opVal = opcode.PUSHT
 	}
-	Instruction(w, opcode.CONVERT, []byte{byte(stackitem.BooleanT)})
+	Opcodes(w, opVal, opcode.NOT)
 }
 
 func padRight(s int, buf []byte) []byte {
diff --git a/pkg/vm/emit/emit_test.go b/pkg/vm/emit/emit_test.go
index f2f135725..130cc5e54 100644
--- a/pkg/vm/emit/emit_test.go
+++ b/pkg/vm/emit/emit_test.go
@@ -231,35 +231,34 @@ func TestEmitArray(t *testing.T) {
 		assert.EqualValues(t, opcode.PUSHDATA1, res[0])
 		assert.EqualValues(t, 2, res[1])
 		assert.EqualValues(t, []byte{0xCA, 0xFE}, res[2:4])
-		assert.EqualValues(t, opcode.PUSHT, res[4])
-		assert.EqualValues(t, opcode.CONVERT, res[5])
-		assert.EqualValues(t, stackitem.BooleanT, res[6])
-		assert.EqualValues(t, opcode.PUSHDATA1, res[7])
-		assert.EqualValues(t, 3, res[8])
-		assert.EqualValues(t, []byte("str"), res[9:12])
-		assert.EqualValues(t, opcode.PUSH1, res[12])
-		assert.EqualValues(t, opcode.PUSHNULL, res[13])
-		assert.EqualValues(t, opcode.PUSH2, res[14])
-		assert.EqualValues(t, opcode.PUSH1, res[15])
-		assert.EqualValues(t, opcode.PUSH2, res[16])
-		assert.EqualValues(t, opcode.PACK, res[17])
-		assert.EqualValues(t, opcode.PUSHINT128, res[18])
-		assert.EqualValues(t, veryBig, bigint.FromBytes(res[19:35]))
-		assert.EqualValues(t, opcode.PUSH0, res[35])
-		assert.EqualValues(t, opcode.PUSHDATA1, res[36])
-		assert.EqualValues(t, 32, res[37])
-		assert.EqualValues(t, u256.BytesBE(), res[38:70])
-		assert.EqualValues(t, opcode.PUSHDATA1, res[70])
-		assert.EqualValues(t, 20, res[71])
-		assert.EqualValues(t, u160.BytesBE(), res[72:92])
-		assert.EqualValues(t, opcode.PUSHDATA1, res[92])
-		assert.EqualValues(t, 32, res[93])
-		assert.EqualValues(t, u256.BytesBE(), res[94:126])
-		assert.EqualValues(t, opcode.PUSHDATA1, res[126])
-		assert.EqualValues(t, 20, res[127])
-		assert.EqualValues(t, u160.BytesBE(), res[128:148])
+		assert.EqualValues(t, opcode.PUSHF, res[4])
+		assert.EqualValues(t, opcode.NOT, res[5])
+		assert.EqualValues(t, opcode.PUSHDATA1, res[6])
+		assert.EqualValues(t, 3, res[7])
+		assert.EqualValues(t, []byte("str"), res[8:11])
+		assert.EqualValues(t, opcode.PUSH1, res[11])
+		assert.EqualValues(t, opcode.PUSHNULL, res[12])
+		assert.EqualValues(t, opcode.PUSH2, res[13])
+		assert.EqualValues(t, opcode.PUSH1, res[14])
+		assert.EqualValues(t, opcode.PUSH2, res[15])
+		assert.EqualValues(t, opcode.PACK, res[16])
+		assert.EqualValues(t, opcode.PUSHINT128, res[17])
+		assert.EqualValues(t, veryBig, bigint.FromBytes(res[18:34]))
+		assert.EqualValues(t, opcode.PUSH0, res[34])
+		assert.EqualValues(t, opcode.PUSHDATA1, res[35])
+		assert.EqualValues(t, 32, res[36])
+		assert.EqualValues(t, u256.BytesBE(), res[37:69])
+		assert.EqualValues(t, opcode.PUSHDATA1, res[69])
+		assert.EqualValues(t, 20, res[70])
+		assert.EqualValues(t, u160.BytesBE(), res[71:91])
+		assert.EqualValues(t, opcode.PUSHDATA1, res[91])
+		assert.EqualValues(t, 32, res[92])
+		assert.EqualValues(t, u256.BytesBE(), res[93:125])
+		assert.EqualValues(t, opcode.PUSHDATA1, res[125])
+		assert.EqualValues(t, 20, res[126])
+		assert.EqualValues(t, u160.BytesBE(), res[127:147])
+		assert.EqualValues(t, opcode.PUSHNULL, res[147])
 		assert.EqualValues(t, opcode.PUSHNULL, res[148])
-		assert.EqualValues(t, opcode.PUSHNULL, res[149])
 	})
 
 	t.Run("empty", func(t *testing.T) {
@@ -281,12 +280,10 @@ func TestEmitBool(t *testing.T) {
 	Bool(buf.BinWriter, true)
 	Bool(buf.BinWriter, false)
 	result := buf.Bytes()
-	assert.EqualValues(t, opcode.PUSH1, result[0])
-	assert.EqualValues(t, opcode.CONVERT, result[1])
-	assert.EqualValues(t, stackitem.BooleanT, result[2])
-	assert.EqualValues(t, opcode.PUSH0, result[3])
-	assert.EqualValues(t, opcode.CONVERT, result[4])
-	assert.EqualValues(t, stackitem.BooleanT, result[5])
+	assert.EqualValues(t, opcode.PUSH0, result[0])
+	assert.EqualValues(t, opcode.NOT, result[1])
+	assert.EqualValues(t, opcode.PUSH1, result[2])
+	assert.EqualValues(t, opcode.NOT, result[3])
 }
 
 func TestEmitOpcode(t *testing.T) {