diff --git a/pkg/compiler/codegen.go b/pkg/compiler/codegen.go
index 4de352221..089660638 100644
--- a/pkg/compiler/codegen.go
+++ b/pkg/compiler/codegen.go
@@ -446,7 +446,7 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
 			// RHS can contain exactly one expression, thus there is no need to iterate.
 			ast.Walk(c, n.Lhs[0])
 			ast.Walk(c, n.Rhs[0])
-			c.convertToken(n.Tok)
+			c.emitToken(n.Tok, c.typeOf(n.Rhs[0]))
 		}
 		for i := 0; i < len(n.Lhs); i++ {
 			switch t := n.Lhs[i].(type) {
@@ -581,7 +581,7 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
 	case *ast.SwitchStmt:
 		ast.Walk(c, n.Tag)
 
-		eqOpcode := c.getEqualityOpcode(n.Tag)
+		eqOpcode, _ := convertToken(token.EQL, c.typeOf(n.Tag))
 		switchEnd, label := c.generateLabel(labelEnd)
 
 		lastSwitch := c.currentSwitch
@@ -735,28 +735,7 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
 		default:
 			ast.Walk(c, n.X)
 			ast.Walk(c, n.Y)
-			switch {
-			case n.Op == token.ADD:
-				// VM has separate opcodes for number and string concatenation
-				if isString(tinfo.Type) {
-					emit.Opcode(c.prog.BinWriter, opcode.CAT)
-				} else {
-					emit.Opcode(c.prog.BinWriter, opcode.ADD)
-				}
-			case n.Op == token.EQL:
-				// VM has separate opcodes for number and string equality
-				op := c.getEqualityOpcode(n.X)
-				emit.Opcode(c.prog.BinWriter, op)
-			case n.Op == token.NEQ:
-				// VM has separate opcodes for number and string equality
-				if isString(c.typeOf(n.X)) {
-					emit.Opcode(c.prog.BinWriter, opcode.NOTEQUAL)
-				} else {
-					emit.Opcode(c.prog.BinWriter, opcode.NUMNOTEQUAL)
-				}
-			default:
-				c.convertToken(n.Op)
-			}
+			c.emitToken(n.Op, c.typeOf(n.X))
 			return nil
 		}
 
@@ -925,7 +904,7 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
 
 	case *ast.IncDecStmt:
 		ast.Walk(c, n.X)
-		c.convertToken(n.Tok)
+		c.emitToken(n.Tok, c.typeOf(n.X))
 
 		// For now only identifiers are supported for (post) for stmts.
 		// for i := 0; i < 10; i++ {}
@@ -1205,15 +1184,6 @@ func (c *codegen) getLabelOffset(typ labelOffsetType, name string) uint16 {
 	return c.labels[labelWithType{name: name, typ: typ}]
 }
 
-func (c *codegen) getEqualityOpcode(expr ast.Expr) opcode.Opcode {
-	t, ok := c.typeOf(expr).Underlying().(*types.Basic)
-	if ok && t.Info()&types.IsNumeric != 0 {
-		return opcode.NUMEQUAL
-	}
-
-	return opcode.EQUAL
-}
-
 // getByteArray returns byte array value from constant expr.
 // Only literals are supported.
 func (c *codegen) getByteArray(expr ast.Expr) []byte {
@@ -1459,59 +1429,79 @@ func (c *codegen) convertStruct(lit *ast.CompositeLit, ptr bool) {
 	}
 }
 
-func (c *codegen) convertToken(tok token.Token) {
+func (c *codegen) emitToken(tok token.Token, typ types.Type) {
+	op, err := convertToken(tok, typ)
+	if err != nil {
+		c.prog.Err = err
+		return
+	}
+	emit.Opcode(c.prog.BinWriter, op)
+}
+
+func convertToken(tok token.Token, typ types.Type) (opcode.Opcode, error) {
 	switch tok {
 	case token.ADD_ASSIGN:
-		emit.Opcode(c.prog.BinWriter, opcode.ADD)
+		return opcode.ADD, nil
 	case token.SUB_ASSIGN:
-		emit.Opcode(c.prog.BinWriter, opcode.SUB)
+		return opcode.SUB, nil
 	case token.MUL_ASSIGN:
-		emit.Opcode(c.prog.BinWriter, opcode.MUL)
+		return opcode.MUL, nil
 	case token.QUO_ASSIGN:
-		emit.Opcode(c.prog.BinWriter, opcode.DIV)
+		return opcode.DIV, nil
 	case token.REM_ASSIGN:
-		emit.Opcode(c.prog.BinWriter, opcode.MOD)
+		return opcode.MOD, nil
 	case token.ADD:
-		emit.Opcode(c.prog.BinWriter, opcode.ADD)
+		// VM has separate opcodes for number and string concatenation
+		if isString(typ) {
+			return opcode.CAT, nil
+		}
+		return opcode.ADD, nil
 	case token.SUB:
-		emit.Opcode(c.prog.BinWriter, opcode.SUB)
+		return opcode.SUB, nil
 	case token.MUL:
-		emit.Opcode(c.prog.BinWriter, opcode.MUL)
+		return opcode.MUL, nil
 	case token.QUO:
-		emit.Opcode(c.prog.BinWriter, opcode.DIV)
+		return opcode.DIV, nil
 	case token.REM:
-		emit.Opcode(c.prog.BinWriter, opcode.MOD)
+		return opcode.MOD, nil
 	case token.LSS:
-		emit.Opcode(c.prog.BinWriter, opcode.LT)
+		return opcode.LT, nil
 	case token.LEQ:
-		emit.Opcode(c.prog.BinWriter, opcode.LTE)
+		return opcode.LTE, nil
 	case token.GTR:
-		emit.Opcode(c.prog.BinWriter, opcode.GT)
+		return opcode.GT, nil
 	case token.GEQ:
-		emit.Opcode(c.prog.BinWriter, opcode.GTE)
+		return opcode.GTE, nil
 	case token.EQL:
-		emit.Opcode(c.prog.BinWriter, opcode.NUMEQUAL)
+		// VM has separate opcodes for number and string equality
+		if isNumber(typ) {
+			return opcode.NUMEQUAL, nil
+		}
+		return opcode.EQUAL, nil
 	case token.NEQ:
-		emit.Opcode(c.prog.BinWriter, opcode.NUMNOTEQUAL)
+		// VM has separate opcodes for number and string equality
+		if isNumber(typ) {
+			return opcode.NUMNOTEQUAL, nil
+		}
+		return opcode.NOTEQUAL, nil
 	case token.DEC:
-		emit.Opcode(c.prog.BinWriter, opcode.DEC)
+		return opcode.DEC, nil
 	case token.INC:
-		emit.Opcode(c.prog.BinWriter, opcode.INC)
+		return opcode.INC, nil
 	case token.NOT:
-		emit.Opcode(c.prog.BinWriter, opcode.NOT)
+		return opcode.NOT, nil
 	case token.AND:
-		emit.Opcode(c.prog.BinWriter, opcode.AND)
+		return opcode.AND, nil
 	case token.OR:
-		emit.Opcode(c.prog.BinWriter, opcode.OR)
+		return opcode.OR, nil
 	case token.SHL:
-		emit.Opcode(c.prog.BinWriter, opcode.SHL)
+		return opcode.SHL, nil
 	case token.SHR:
-		emit.Opcode(c.prog.BinWriter, opcode.SHR)
+		return opcode.SHR, nil
 	case token.XOR:
-		emit.Opcode(c.prog.BinWriter, opcode.XOR)
+		return opcode.XOR, nil
 	default:
-		c.prog.Err = fmt.Errorf("compiler could not convert token: %s", tok)
-		return
+		return 0, fmt.Errorf("compiler could not convert token: %s", tok)
 	}
 }
 
diff --git a/pkg/compiler/codegen_test.go b/pkg/compiler/codegen_test.go
index b499771d8..9245edef9 100644
--- a/pkg/compiler/codegen_test.go
+++ b/pkg/compiler/codegen_test.go
@@ -2,9 +2,9 @@ package compiler
 
 import (
 	"go/token"
+	"go/types"
 	"testing"
 
-	"github.com/nspcc-dev/neo-go/pkg/io"
 	"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
 	"github.com/stretchr/testify/assert"
 )
@@ -14,59 +14,74 @@ func TestConvertToken(t *testing.T) {
 		name   string
 		token  token.Token
 		opcode opcode.Opcode
+		typ    types.Type
 	}
 
 	testCases := []testCase{
-		{"ADD",
+		{"ADD (string)",
 			token.ADD,
 			opcode.ADD,
+			types.Typ[types.Int],
+		},
+		{"ADD (number)",
+			token.ADD,
+			opcode.CAT,
+			types.Typ[types.String],
 		},
 		{"SUB",
 			token.SUB,
 			opcode.SUB,
+			nil,
 		},
 		{"MUL",
 			token.MUL,
 			opcode.MUL,
+			nil,
 		},
 		{"QUO",
 			token.QUO,
 			opcode.DIV,
+			nil,
 		},
 		{"REM",
 			token.REM,
 			opcode.MOD,
+			nil,
 		},
 		{"ADD_ASSIGN",
 			token.ADD_ASSIGN,
 			opcode.ADD,
+			nil,
 		},
 		{"SUB_ASSIGN",
 			token.SUB_ASSIGN,
 			opcode.SUB,
+			nil,
 		},
 		{"MUL_ASSIGN",
 			token.MUL_ASSIGN,
 			opcode.MUL,
+			nil,
 		},
 		{"QUO_ASSIGN",
 			token.QUO_ASSIGN,
 			opcode.DIV,
+			nil,
 		},
 		{"REM_ASSIGN",
 			token.REM_ASSIGN,
 			opcode.MOD,
+			nil,
 		},
 	}
 
 	for _, tcase := range testCases {
-		t.Run(tcase.name, func(t *testing.T) { eval(t, tcase.token, tcase.opcode) })
+		t.Run(tcase.name, func(t *testing.T) { eval(t, tcase.token, tcase.opcode, tcase.typ) })
 	}
 }
 
-func eval(t *testing.T, token token.Token, opcode opcode.Opcode) {
-	codegen := &codegen{prog: io.NewBufBinWriter()}
-	codegen.convertToken(token)
-	readOpcode := codegen.prog.Bytes()
-	assert.Equal(t, []byte{byte(opcode)}, readOpcode)
+func eval(t *testing.T, token token.Token, opcode opcode.Opcode, typ types.Type) {
+	op, err := convertToken(token, typ)
+	assert.NoError(t, err)
+	assert.Equal(t, opcode, op)
 }
diff --git a/pkg/compiler/types.go b/pkg/compiler/types.go
index 77bbcfc1c..e03dcf286 100644
--- a/pkg/compiler/types.go
+++ b/pkg/compiler/types.go
@@ -31,6 +31,11 @@ func isByte(typ types.Type) bool {
 	return isBasicTypeOfKind(typ, types.Uint8, types.Int8)
 }
 
+func isNumber(typ types.Type) bool {
+	t, ok := typ.Underlying().(*types.Basic)
+	return ok && t.Info()&types.IsNumeric != 0
+}
+
 func isString(typ types.Type) bool {
 	return isBasicTypeOfKind(typ, types.String)
 }