diff --git a/client/llb/fileop.go b/client/llb/fileop.go
index 64f6ea312860..d41f9e4cb09b 100644
--- a/client/llb/fileop.go
+++ b/client/llb/fileop.go
@@ -239,7 +239,7 @@ func (up *UserOpt) marshal(base pb.InputIndex) *pb.UserOpt {
 	if up.Name != "" {
 		return &pb.UserOpt{Name: up.Name, Input: base}
 	}
-	return &pb.UserOpt{Id: int32(up.UID), Input: -1}
+	return &pb.UserOpt{Id: uint32(up.UID), Input: -1}
 }
 
 func Mkfile(p string, m os.FileMode, dt []byte, opts ...MkfileOption) *FileAction {
diff --git a/solver/pb/ops.pb.go b/solver/pb/ops.pb.go
index c97ab285624a..dc427008efd6 100644
--- a/solver/pb/ops.pb.go
+++ b/solver/pb/ops.pb.go
@@ -1413,7 +1413,7 @@ func (m *ChownOpt) GetGroup() *UserOpt {
 type UserOpt struct {
 	Name  string     `protobuf:"bytes,1,opt,name=name,proto3" json:"name,omitempty"`
 	Input InputIndex `protobuf:"varint,2,opt,name=input,proto3,customtype=InputIndex" json:"input"`
-	Id    int32      `protobuf:"varint,3,opt,name=id,proto3" json:"id,omitempty"`
+	Id    uint32     `protobuf:"varint,3,opt,name=id,proto3" json:"id,omitempty"`
 }
 
 func (m *UserOpt) Reset()                    { *m = UserOpt{} }
@@ -1428,7 +1428,7 @@ func (m *UserOpt) GetName() string {
 	return ""
 }
 
-func (m *UserOpt) GetId() int32 {
+func (m *UserOpt) GetId() uint32 {
 	if m != nil {
 		return m.Id
 	}
@@ -8021,7 +8021,7 @@ func (m *UserOpt) Unmarshal(dAtA []byte) error {
 				}
 				b := dAtA[iNdEx]
 				iNdEx++
-				m.Id |= (int32(b) & 0x7F) << shift
+				m.Id |= (uint32(b) & 0x7F) << shift
 				if b < 0x80 {
 					break
 				}
@@ -8155,7 +8155,7 @@ var (
 func init() { proto.RegisterFile("ops.proto", fileDescriptorOps) }
 
 var fileDescriptorOps = []byte{
-	// 1867 bytes of a gzipped FileDescriptorProto
+	// 1866 bytes of a gzipped FileDescriptorProto
 	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xbc, 0x58, 0xcd, 0x6e, 0x23, 0xc7,
 	0x11, 0x16, 0x87, 0xff, 0x45, 0x49, 0xcb, 0xb4, 0xd7, 0x1b, 0x46, 0xd9, 0x48, 0xf2, 0xd8, 0x31,
 	0xe8, 0xfd, 0xa1, 0x00, 0x19, 0xb0, 0x0d, 0x1f, 0x82, 0x48, 0x22, 0x17, 0x62, 0x9c, 0x15, 0x85,
@@ -8262,15 +8262,15 @@ var fileDescriptorOps = []byte{
 	0x01, 0x2f, 0xde, 0x10, 0x70, 0xf7, 0x0c, 0x6a, 0xa9, 0x81, 0x6c, 0xcf, 0x7e, 0x1a, 0x15, 0xb2,
 	0x6f, 0xee, 0xa7, 0x89, 0x50, 0x68, 0xbb, 0xf9, 0x4e, 0xfa, 0x08, 0xca, 0x63, 0x25, 0xe7, 0xb1,
 	0x7d, 0x35, 0x57, 0x18, 0x46, 0xe2, 0x3e, 0x87, 0xaa, 0x45, 0xd0, 0xf4, 0xc8, 0x9b, 0xa5, 0x1f,
-	0xc8, 0x34, 0xce, 0x1e, 0x37, 0xe7, 0x6d, 0x8f, 0xdb, 0x36, 0x38, 0xb6, 0xfd, 0x2d, 0x73, 0x27,
-	0x0c, 0xee, 0xb5, 0xa1, 0x6a, 0x3f, 0x06, 0x59, 0x1d, 0xca, 0x4f, 0xcf, 0x86, 0xbd, 0x27, 0xcd,
-	0x0d, 0x56, 0x83, 0xd2, 0xe9, 0x60, 0xf8, 0xa4, 0x59, 0xc0, 0xd1, 0xd9, 0xe0, 0xac, 0xd7, 0x74,
-	0xee, 0xfd, 0x1c, 0xea, 0xcb, 0x8f, 0x16, 0x84, 0x8f, 0xfb, 0x67, 0xdd, 0xe6, 0x06, 0x03, 0xa8,
-	0x0c, 0x7b, 0x27, 0xbc, 0x87, 0xe4, 0x2a, 0x14, 0x87, 0xc3, 0xd3, 0xa6, 0x83, 0xaa, 0x4e, 0x8e,
-	0x4e, 0x4e, 0x7b, 0xcd, 0x22, 0x0e, 0x9f, 0x3c, 0x3e, 0x7f, 0x34, 0x6c, 0x96, 0xee, 0x7d, 0x01,
-	0xb7, 0xd6, 0x3e, 0x1a, 0x68, 0xf5, 0xe9, 0x11, 0xef, 0xa1, 0xa6, 0x06, 0x54, 0xcf, 0x79, 0xff,
-	0xd9, 0xd1, 0x93, 0x5e, 0xb3, 0x80, 0x82, 0x5f, 0x0e, 0x4e, 0xbe, 0xe9, 0x75, 0x9b, 0xce, 0xf1,
-	0xed, 0xef, 0x5e, 0xef, 0x16, 0xfe, 0xf4, 0x7a, 0xb7, 0xf0, 0xd7, 0xd7, 0xbb, 0x85, 0x7f, 0xbe,
-	0xde, 0x2d, 0x7c, 0xfb, 0xaf, 0xdd, 0x8d, 0x8b, 0x0a, 0xfd, 0xd1, 0xf2, 0xf9, 0xbf, 0x03, 0x00,
-	0x00, 0xff, 0xff, 0x41, 0x4c, 0xd7, 0xab, 0xa8, 0x11, 0x00, 0x00,
+	0xc8, 0x34, 0xce, 0x1e, 0x37, 0xe7, 0x6d, 0x8f, 0xdb, 0x36, 0x38, 0xcb, 0xf6, 0xd7, 0x09, 0x83,
+	0x7b, 0x6d, 0xa8, 0xda, 0x8f, 0x41, 0x56, 0x87, 0xf2, 0xd3, 0xb3, 0x61, 0xef, 0x49, 0x73, 0x83,
+	0xd5, 0xa0, 0x74, 0x3a, 0x18, 0x3e, 0x69, 0x16, 0x70, 0x74, 0x36, 0x38, 0xeb, 0x35, 0x9d, 0x7b,
+	0x3f, 0x87, 0xfa, 0xf2, 0xa3, 0x05, 0xe1, 0xe3, 0xfe, 0x59, 0xb7, 0xb9, 0xc1, 0x00, 0x2a, 0xc3,
+	0xde, 0x09, 0xef, 0x21, 0xb9, 0x0a, 0xc5, 0xe1, 0xf0, 0xb4, 0xe9, 0xa0, 0xaa, 0x93, 0xa3, 0x93,
+	0xd3, 0x5e, 0xb3, 0x88, 0xc3, 0x27, 0x8f, 0xcf, 0x1f, 0x0d, 0x9b, 0xa5, 0x7b, 0x5f, 0xc0, 0xad,
+	0xb5, 0x8f, 0x06, 0x5a, 0x7d, 0x7a, 0xc4, 0x7b, 0xa8, 0xa9, 0x01, 0xd5, 0x73, 0xde, 0x7f, 0x76,
+	0xf4, 0xa4, 0xd7, 0x2c, 0xa0, 0xe0, 0x97, 0x83, 0x93, 0x6f, 0x7a, 0xdd, 0xa6, 0x73, 0x7c, 0xfb,
+	0xbb, 0xd7, 0xbb, 0x85, 0x3f, 0xbd, 0xde, 0x2d, 0xfc, 0xf5, 0xf5, 0x6e, 0xe1, 0x9f, 0xaf, 0x77,
+	0x0b, 0xdf, 0xfe, 0x6b, 0x77, 0xe3, 0xa2, 0x42, 0x7f, 0xb4, 0x7c, 0xfe, 0xef, 0x00, 0x00, 0x00,
+	0xff, 0xff, 0xe3, 0xa1, 0x74, 0x29, 0xa8, 0x11, 0x00, 0x00,
 }
diff --git a/solver/pb/ops.proto b/solver/pb/ops.proto
index fa78c4aa875f..9051053d24f3 100644
--- a/solver/pb/ops.proto
+++ b/solver/pb/ops.proto
@@ -261,5 +261,5 @@ message ChownOpt {
 message UserOpt {
 	string name = 1;
 	int64 input = 2 [(gogoproto.customtype) = "InputIndex", (gogoproto.nullable) = false]; // input that contains /etc/passwd if using a name
-	int32 id = 3;
+	uint32 id = 3;
 }
\ No newline at end of file