diff --git a/hcloud/error.go b/hcloud/error.go
index 653043e6..2b5c4930 100644
--- a/hcloud/error.go
+++ b/hcloud/error.go
@@ -1,6 +1,7 @@
 package hcloud
 
 import (
+	"errors"
 	"fmt"
 	"net"
 )
@@ -120,7 +121,8 @@ type ErrorDetailsInvalidInputField struct {
 
 // IsError returns whether err is an API error with the given error code.
 func IsError(err error, code ErrorCode) bool {
-	apiErr, ok := err.(Error)
+	var apiErr Error
+	ok := errors.As(err, &apiErr)
 	return ok && apiErr.Code == code
 }
 
diff --git a/hcloud/error_test.go b/hcloud/error_test.go
new file mode 100644
index 00000000..300added
--- /dev/null
+++ b/hcloud/error_test.go
@@ -0,0 +1,101 @@
+package hcloud
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestError_Error(t *testing.T) {
+	type fields struct {
+		Code     ErrorCode
+		Message  string
+		Details  interface{}
+		response *Response
+	}
+	tests := []struct {
+		name   string
+		fields fields
+		want   string
+	}{
+		{
+			name: "simple error",
+			fields: fields{
+				Code:    ErrorCodeUnauthorized,
+				Message: "unable to authenticate",
+			},
+			want: "unable to authenticate (unauthorized)",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			e := Error{
+				Code:     tt.fields.Code,
+				Message:  tt.fields.Message,
+				Details:  tt.fields.Details,
+				response: tt.fields.response,
+			}
+			assert.Equalf(t, tt.want, e.Error(), "Error()")
+		})
+	}
+}
+
+func TestIsError(t *testing.T) {
+	type args struct {
+		err  error
+		code ErrorCode
+	}
+	tests := []struct {
+		name string
+		args args
+		want bool
+	}{
+		{
+			name: "hcloud error with code",
+			args: args{
+				err:  Error{Code: ErrorCodeUnauthorized},
+				code: ErrorCodeUnauthorized,
+			},
+			want: true,
+		},
+		{
+			name: "hcloud error with different code",
+			args: args{
+				err:  Error{Code: ErrorCodeConflict},
+				code: ErrorCodeUnauthorized,
+			},
+			want: false,
+		},
+		{
+			name: "wrapped hcloud error with code",
+			args: args{
+				err:  fmt.Errorf("wrapped: %w", Error{Code: ErrorCodeUnauthorized}),
+				code: ErrorCodeUnauthorized,
+			},
+			want: true,
+		},
+		{
+			name: "wrapped hcloud error with different code",
+			args: args{
+				err:  fmt.Errorf("wrapped: %w", Error{Code: ErrorCodeConflict}),
+				code: ErrorCodeUnauthorized,
+			},
+			want: false,
+		},
+		{
+			name: "non-hcloud error",
+			args: args{
+				err:  fmt.Errorf("something went wrong"),
+				code: ErrorCodeUnauthorized,
+			},
+			want: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert.Equalf(t, tt.want, IsError(tt.args.err, tt.args.code), "IsError(%v, %v)", tt.args.err, tt.args.code)
+		})
+	}
+}