diff --git a/pkg/compiler/codegen.go b/pkg/compiler/codegen.go
index d1e36f75c..7c4cfa30b 100644
--- a/pkg/compiler/codegen.go
+++ b/pkg/compiler/codegen.go
@@ -617,25 +617,31 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
 			ast.Walk(c, n.X)
 			ast.Walk(c, n.Y)
 
-			switch {
-			case n.Op == token.ADD:
+			switch n.Op {
+			case token.ADD:
 				// VM has separate opcodes for number and string concatenation
 				if isStringType(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 isStringType(c.typeInfo.Types[n.X].Type) {
-					emit.Opcode(c.prog.BinWriter, opcode.EQUAL)
-					emit.Opcode(c.prog.BinWriter, opcode.NOT)
+			case token.EQL, token.NEQ:
+				if isExprNil(n.X) || isExprNil(n.Y) {
+					c.prog.Err = errors.New("comparison with `nil` is not supported, use `len(..) == 0` instead")
+					return nil
+				}
+				if n.Op == token.EQL {
+					// VM has separate opcodes for number and string equality
+					op := c.getEqualityOpcode(n.X)
+					emit.Opcode(c.prog.BinWriter, op)
 				} else {
-					emit.Opcode(c.prog.BinWriter, opcode.NUMNOTEQUAL)
+					// VM has separate opcodes for number and string equality
+					if isStringType(c.typeInfo.Types[n.X].Type) {
+						emit.Opcode(c.prog.BinWriter, opcode.EQUAL)
+						emit.Opcode(c.prog.BinWriter, opcode.NOT)
+					} else {
+						emit.Opcode(c.prog.BinWriter, opcode.NUMNOTEQUAL)
+					}
 				}
 			default:
 				c.convertToken(n.Op)
diff --git a/pkg/compiler/slice_test.go b/pkg/compiler/slice_test.go
index ca4c25798..d1f77a369 100644
--- a/pkg/compiler/slice_test.go
+++ b/pkg/compiler/slice_test.go
@@ -1,10 +1,14 @@
 package compiler_test
 
 import (
+	"fmt"
 	"math/big"
+	"strings"
 	"testing"
 
+	"github.com/nspcc-dev/neo-go/pkg/compiler"
 	"github.com/nspcc-dev/neo-go/pkg/vm"
+	"github.com/stretchr/testify/require"
 )
 
 var sliceTestCases = []testCase{
@@ -175,6 +179,31 @@ func TestSliceOperations(t *testing.T) {
 	runTestCases(t, sliceTestCases)
 }
 
+func TestSliceEmpty(t *testing.T) {
+	srcTmpl := `package foo
+	func Main() int {
+		var a []int
+		%s
+		if %s {
+			return 1
+		}
+		return 2
+	}`
+	t.Run("WithNil", func(t *testing.T) {
+		src := fmt.Sprintf(srcTmpl, "", "a == nil")
+		_, err := compiler.Compile(strings.NewReader(src))
+		require.Error(t, err)
+	})
+	t.Run("WithLen", func(t *testing.T) {
+		src := fmt.Sprintf(srcTmpl, "", "len(a) == 0")
+		eval(t, src, big.NewInt(1))
+	})
+	t.Run("NonEmpty", func(t *testing.T) {
+		src := fmt.Sprintf(srcTmpl, "a = []int{1}", "len(a) == 0")
+		eval(t, src, big.NewInt(2))
+	})
+}
+
 func TestJumps(t *testing.T) {
 	src := `
 	package foo