diff --git a/mpt_api_client/rql/__init__.py b/mpt_api_client/rql/__init__.py
index 306117a2..d1a0414c 100644
--- a/mpt_api_client/rql/__init__.py
+++ b/mpt_api_client/rql/__init__.py
@@ -1,3 +1,3 @@
-from mpt_api_client.rql.query_builder import RQLQuery
+from mpt_api_client.rql.query_builder import Property, RQLQuery, Value
 
-__all__ = ["RQLQuery"]  # noqa: WPS410
+__all__ = ["Property", "RQLQuery", "Value"]  # noqa: WPS410
diff --git a/mpt_api_client/rql/query_builder.py b/mpt_api_client/rql/query_builder.py
index c1b05212..02135c97 100644
--- a/mpt_api_client/rql/query_builder.py
+++ b/mpt_api_client/rql/query_builder.py
@@ -9,6 +9,38 @@
 QueryValue = str | bool | dt.date | dt.datetime | Numeric
 
 
+class Property:
+    """Wrapper for model properties in RQL queries."""
+
+    def __init__(self, value: str) -> None:
+        self.value = value
+
+    @override
+    def __str__(self) -> str:
+        return self.value
+
+
+class Value:
+    """Wrapper for literal values in RQL queries."""
+
+    def __init__(self, value: QueryValue) -> None:
+        self.value = value
+
+    @override
+    def __str__(self) -> str:
+        if isinstance(self.value, str):
+            return f"'{self.value}'"
+        if isinstance(self.value, bool):
+            return "true" if self.value else "false"
+
+        if isinstance(self.value, dt.date | dt.datetime):
+            str_time = self.value.isoformat()
+            return f"'{str_time}'"
+
+        # Matching: if isinstance(value, int | float | Decimal):
+        return str(self.value)
+
+
 def parse_kwargs(query_dict: dict[str, QueryValue]) -> list[str]:  # noqa: WPS231
     """
     Parse keyword arguments into RQL query expressions.
@@ -62,16 +94,14 @@ def parse_kwargs(query_dict: dict[str, QueryValue]) -> list[str]:  # noqa: WPS23
     return query
 
 
-def query_value_str(value: QueryValue) -> str:
+def query_value_str(value: Any) -> str:
     """Converts a value to string for use in RQL queries."""
-    if isinstance(value, str):
-        return value
-    if isinstance(value, bool):
-        return "true" if value else "false"
-
-    if isinstance(value, dt.date | dt.datetime):
-        return value.isoformat()
-    # Matching: if isinstance(value, int | float | Decimal):
+    if isinstance(value, QueryValue):
+        value = Value(value)
+    if isinstance(value, Value):
+        return str(value)
+    if isinstance(value, Property):
+        return str(value)
     return str(value)
 
 
@@ -104,10 +134,10 @@ def rql_encode(op: str, value: Any) -> str:
         rql_encode('in', ['a', 'b', 'c'])
         'a,b,c'
     """
-    if op not in constants.LIST and isinstance(value, QueryValue):
+    if op not in constants.LIST and isinstance(value, QueryValue | Value | Property):
         return query_value_str(value)
     if op in constants.LIST and isinstance(value, list | tuple | set):
-        return ",".join(str(el) for el in value)
+        return ",".join(query_value_str(el) for el in value)
 
     raise TypeError(f"the `{op}` operator doesn't support the {type(value)} type.")
 
diff --git a/tests/unit/http/mixins/test_collection_mixin.py b/tests/unit/http/mixins/test_collection_mixin.py
index bafb5acc..646b6fab 100644
--- a/tests/unit/http/mixins/test_collection_mixin.py
+++ b/tests/unit/http/mixins/test_collection_mixin.py
@@ -73,7 +73,7 @@ def test_col_mx_fetch_one_with_filters(
     assert first_request.url == (
         "https://api.example.com/api/v1/test"
         "?limit=1&offset=0&order=created"
-        "&select=id,name&eq(status,active)"
+        "&select=id,name&eq(status,'active')"
     )
 
 
@@ -91,7 +91,7 @@ def test_col_mx_fetch_page_with_filter(
         "https://api.example.com/api/v1/test?limit=10&offset=5"
         "&order=-created,name"
         "&select=-audit,product.agreements,-product.agreements.product"
-        "&eq(status,active)"
+        "&eq(status,'active')"
     )
     with respx.mock:
         mock_route = respx.get("https://api.example.com/api/v1/test").mock(
@@ -213,7 +213,7 @@ def test_col_mx_iterate_with_filters(
     request = mock_route.calls[0].request
     assert (
         str(request.url) == "https://api.example.com/api/v1/test"
-        "?limit=100&offset=0&order=created&select=id,name&eq(status,active)"
+        "?limit=100&offset=0&order=created&select=id,name&eq(status,'active')"
     )
 
 
@@ -322,7 +322,7 @@ async def test_async_col_mx_fetch_one_with_filters(
     assert first_request.url == (
         "https://api.example.com/api/v1/test"
         "?limit=1&offset=0&order=created"
-        "&select=id,name&eq(status,active)"
+        "&select=id,name&eq(status,'active')"
     )
 
 
@@ -342,7 +342,7 @@ async def test_async_col_mx_fetch_page_with_filter(
         "https://api.example.com/api/v1/test?limit=10&offset=5"
         "&order=-created,name"
         "&select=-audit,product.agreements,-product.agreements.product"
-        "&eq(status,active)"
+        "&eq(status,'active')"
     )
     with respx.mock:
         mock_route = respx.get("https://api.example.com/api/v1/test").mock(
@@ -464,7 +464,7 @@ async def test_async_col_mx_iterate_with_filters(
     request = mock_route.calls[0].request
     assert (
         str(request.url) == "https://api.example.com/api/v1/test"
-        "?limit=100&offset=0&order=created&select=id,name&eq(status,active)"
+        "?limit=100&offset=0&order=created&select=id,name&eq(status,'active')"
     )
 
 
diff --git a/tests/unit/http/test_base_service.py b/tests/unit/http/test_base_service.py
index 70c2a15a..612bcc84 100644
--- a/tests/unit/http/test_base_service.py
+++ b/tests/unit/http/test_base_service.py
@@ -52,7 +52,7 @@ def test_build_url_with_query_state(http_client, filter_status_active):
 
     result = service_with_state.build_path()
 
-    assert result == "/api/v1/test?order=created,-name&select=id,name&eq(status,active)"
+    assert result == "/api/v1/test?order=created,-name&select=id,name&eq(status,'active')"
 
 
 def test_build_url_with_query_state_and_params(http_client, filter_status_active):
@@ -65,7 +65,7 @@ def test_build_url_with_query_state_and_params(http_client, filter_status_active
 
     result = service_with_state.build_path(query_params)
 
-    assert result == "/api/v2/test/T-123?limit=5&eq(status,active)"
+    assert result == "/api/v2/test/T-123?limit=5&eq(status,'active')"
 
 
 def test_build_url_with_chained_methods(dummy_service, filter_status_active):
@@ -79,6 +79,6 @@ def test_build_url_with_chained_methods(dummy_service, filter_status_active):
     result = chained_service.build_path({"limit": "10"})
 
     expected_url = (
-        "/api/v1/test?limit=10&order=-created,name&select=id,name,-audit&eq(status,active)"
+        "/api/v1/test?limit=10&order=-created,name&select=id,name,-audit&eq(status,'active')"
     )
     assert result == expected_url
diff --git a/tests/unit/http/test_query_state.py b/tests/unit/http/test_query_state.py
index 98e131cf..210029be 100644
--- a/tests/unit/http/test_query_state.py
+++ b/tests/unit/http/test_query_state.py
@@ -30,7 +30,7 @@ def test_build_url(filter_status_active):
     assert result == (
         "order=-created,name"
         "&select=-audit,product.agreements,-product.agreements.product"
-        "&eq(status,active)"
+        "&eq(status,'active')"
     )
 
 
@@ -46,4 +46,4 @@ def test_build_with_params(filter_status_active):
 
     result = query_state.build(query_params)
 
-    assert result == "limit=10&order=created&select=name&eq(status,active)"
+    assert result == "limit=10&order=created&select=name&eq(status,'active')"
diff --git a/tests/unit/rql/query_builder/test_create_rql.py b/tests/unit/rql/query_builder/test_create_rql.py
index 08f6e9cd..deb25e44 100644
--- a/tests/unit/rql/query_builder/test_create_rql.py
+++ b/tests/unit/rql/query_builder/test_create_rql.py
@@ -15,14 +15,14 @@ def test_create_with_field():
     query.eq("value")  # act
 
     assert query.op == RQLQuery.OP_EXPRESSION
-    assert str(query) == "eq(field,value)"
+    assert str(query) == "eq(field,'value')"
 
 
 def test_create_single_kwarg():
     result = RQLQuery(id="ID")
 
     assert result.op == RQLQuery.OP_EXPRESSION
-    assert str(result) == "eq(id,ID)"
+    assert str(result) == "eq(id,'ID')"
     assert result.children == []
     assert result.negated is False
 
@@ -31,14 +31,14 @@ def test_create_multiple_kwargs():  # noqa: WPS218
     result = RQLQuery(id="ID", status__in=("a", "b"), ok=True)
 
     assert result.op == RQLQuery.OP_AND
-    assert str(result) == "and(eq(id,ID),in(status,(a,b)),eq(ok,true))"
+    assert str(result) == "and(eq(id,'ID'),in(status,('a','b')),eq(ok,true))"
     assert len(result.children) == 3
     assert result.children[0].op == RQLQuery.OP_EXPRESSION
     assert result.children[0].children == []
-    assert str(result.children[0]) == "eq(id,ID)"
+    assert str(result.children[0]) == "eq(id,'ID')"
     assert result.children[1].op == RQLQuery.OP_EXPRESSION
     assert result.children[1].children == []
-    assert str(result.children[1]) == "in(status,(a,b))"
+    assert str(result.children[1]) == "in(status,('a','b'))"
     assert result.children[2].op == RQLQuery.OP_EXPRESSION
     assert result.children[2].children == []
     assert str(result.children[2]) == "eq(ok,true)"
diff --git a/tests/unit/rql/query_builder/test_multiple_ops.py b/tests/unit/rql/query_builder/test_multiple_ops.py
index c724773c..c7c1fb36 100644
--- a/tests/unit/rql/query_builder/test_multiple_ops.py
+++ b/tests/unit/rql/query_builder/test_multiple_ops.py
@@ -11,23 +11,26 @@ def test_and_or():  # noqa: WPS218 WPS473 AAA01
     r5 = r1 & r2 & (r3 | r4)
 
     assert r5.op == RQLQuery.OP_AND
-    assert str(r5) == "and(eq(id,ID),eq(field,value),or(eq(other,value2),in(inop,(a,b))))"  # noqa: WPS204
+    assert str(r5) == "and(eq(id,'ID'),eq(field,'value'),or(eq(other,'value2'),in(inop,('a','b'))))"  # noqa: WPS204
 
     r5 = r1 & r2 | r3
 
-    assert str(r5) == "or(and(eq(id,ID),eq(field,value)),eq(other,value2))"
+    assert str(r5) == "or(and(eq(id,'ID'),eq(field,'value')),eq(other,'value2'))"
 
     r5 = r1 & (r2 | r3)
 
-    assert str(r5) == "and(eq(id,ID),or(eq(field,value),eq(other,value2)))"
+    assert str(r5) == "and(eq(id,'ID'),or(eq(field,'value'),eq(other,'value2')))"
 
     r5 = (r1 & r2) | (r3 & r4)
 
-    assert str(r5) == "or(and(eq(id,ID),eq(field,value)),and(eq(other,value2),in(inop,(a,b))))"
+    assert (
+        str(r5)
+        == "or(and(eq(id,'ID'),eq(field,'value')),and(eq(other,'value2'),in(inop,('a','b'))))"
+    )
 
     r5 = (r1 & r2) | ~r3
 
-    assert str(r5) == "or(and(eq(id,ID),eq(field,value)),not(eq(other,value2)))"
+    assert str(r5) == "or(and(eq(id,'ID'),eq(field,'value')),not(eq(other,'value2')))"
 
 
 def test_and_merge():  # noqa: WPS210  AAA01
diff --git a/tests/unit/rql/query_builder/test_properties_values.py b/tests/unit/rql/query_builder/test_properties_values.py
new file mode 100644
index 00000000..d5611a34
--- /dev/null
+++ b/tests/unit/rql/query_builder/test_properties_values.py
@@ -0,0 +1,41 @@
+from mpt_api_client.rql import Property, RQLQuery, Value
+
+
+def test_compare_default_value():
+    query = RQLQuery(agreement__product__id="order.product.id")
+
+    result = str(query)
+
+    assert result == "eq(agreement.product.id,'order.product.id')"
+
+
+def test_compare_quoted():
+    query = RQLQuery(agreement__product__id=Value("order.product.id"))
+
+    result = str(query)
+
+    assert result == "eq(agreement.product.id,'order.product.id')"
+
+
+def test_compare_property():
+    query = RQLQuery(agreement__product__id=Property("order.product.id"))
+
+    result = str(query)
+
+    assert result == "eq(agreement.product.id,order.product.id)"
+
+
+def test_ne_quoted():
+    query = RQLQuery("agreement.product.id")
+
+    result = str(query.ne(Value("order.product.id")))
+
+    assert result == "ne(agreement.product.id,'order.product.id')"
+
+
+def test_ne_property():
+    query = RQLQuery("agreement.product.id")
+
+    result = str(query.ne(Property("order.product.id")))
+
+    assert result == "ne(agreement.product.id,order.product.id)"
diff --git a/tests/unit/rql/query_builder/test_rql.py b/tests/unit/rql/query_builder/test_rql.py
index 5e393a18..bb046e53 100644
--- a/tests/unit/rql/query_builder/test_rql.py
+++ b/tests/unit/rql/query_builder/test_rql.py
@@ -1,13 +1,15 @@
-from mpt_api_client.rql import RQLQuery
+from mpt_api_client.rql import Property, RQLQuery, Value
 
 
 def test_repr():  # noqa: AAA01
-    products = ["PRD-1", "PRD-2"]
-    product_ids = ",".join(products)
+    products = ["PRD-1", Value("PRD-2"), Property("agreement.product.id")]
     expression_query = RQLQuery(product__id__in=products)
     or_expression = RQLQuery(name="Albert") | RQLQuery(surname="Einstein")
 
-    assert repr(expression_query) == f"<RQLQuery(expr) in(product.id,({product_ids}))>"
+    assert (
+        repr(expression_query)
+        == "<RQLQuery(expr) in(product.id,('PRD-1','PRD-2',agreement.product.id))>"
+    )
     assert repr(or_expression) == "<RQLQuery(or)>"
 
 
@@ -28,9 +30,9 @@ def test_bool():  # noqa: AAA01
 
 
 def test_str():  # noqa: AAA01
-    assert str(RQLQuery(id="ID")) == "eq(id,ID)"
-    assert str(~RQLQuery(id="ID")) == "not(eq(id,ID))"
-    assert str(~RQLQuery(id="ID", field="value")) == "not(and(eq(id,ID),eq(field,value)))"
+    assert str(RQLQuery(id="ID")) == "eq(id,'ID')"
+    assert str(~RQLQuery(id="ID")) == "not(eq(id,'ID'))"
+    assert str(~RQLQuery(id="ID", field="value")) == "not(and(eq(id,'ID'),eq(field,'value')))"
     assert not str(RQLQuery())
 
 
diff --git a/tests/unit/rql/query_builder/test_rql_dot_path.py b/tests/unit/rql/query_builder/test_rql_dot_path.py
index a32c819a..897230de 100644
--- a/tests/unit/rql/query_builder/test_rql_dot_path.py
+++ b/tests/unit/rql/query_builder/test_rql_dot_path.py
@@ -3,7 +3,7 @@
 
 import pytest
 
-from mpt_api_client.rql import RQLQuery
+from mpt_api_client.rql import Property, RQLQuery
 
 
 @pytest.mark.parametrize("op", ["eq", "ne", "gt", "ge", "le", "lt"])
@@ -15,8 +15,8 @@ class Test:  # noqa: WPS431
     test = Test()
     today = dt.datetime.now(dt.UTC).date()
     now = dt.datetime.now(dt.UTC)
-    today_expected_result = f"{op}(asset.id,{today.isoformat()})"
-    now_expected_result = f"{op}(asset.id,{now.isoformat()})"
+    today_expected_result = f"{op}(asset.id,'{today.isoformat()}')"
+    now_expected_result = f"{op}(asset.id,'{now.isoformat()}')"
 
     with pytest.raises(TypeError):
         getattr(RQLQuery().asset.id, op)(test)
@@ -29,7 +29,7 @@ class Test:  # noqa: WPS431
 def test_dotted_path_comp_bool_and_str(op):
     result = getattr(RQLQuery().asset.id, op)
 
-    assert str(result("value")) == f"{op}(asset.id,value)"
+    assert str(result("value")) == f"{op}(asset.id,'value')"
     assert str(result(True)) == f"{op}(asset.id,true)"  # noqa: FBT003
     assert str(result(False)) == f"{op}(asset.id,false)"  # noqa: FBT003
 
@@ -52,10 +52,10 @@ def test_dotted_path_comp_numerics(op):
 def test_dotted_path_search(op):
     result = getattr(RQLQuery().asset.id, op)
 
-    assert str(result("value")) == f"{op}(asset.id,value)"
-    assert str(result("*value")) == f"{op}(asset.id,*value)"
-    assert str(result("value*")) == f"{op}(asset.id,value*)"
-    assert str(result("*value*")) == f"{op}(asset.id,*value*)"
+    assert str(result("value")) == f"{op}(asset.id,'value')"
+    assert str(result("*value")) == f"{op}(asset.id,'*value')"
+    assert str(result("value*")) == f"{op}(asset.id,'value*')"
+    assert str(result("*value*")) == f"{op}(asset.id,'*value*')"
 
 
 @pytest.mark.parametrize(
@@ -67,14 +67,15 @@ def test_dotted_path_search(op):
     ],
 )
 def test_dotted_path_list(method, op):  # noqa: AAA01
-    rexpr_set = getattr(RQLQuery().asset.id, method)(("first", "second"))
-    rexpr_list = getattr(RQLQuery().asset.id, method)(["first", "second"])
+    third = Property("third")
+    rexpr_set = getattr(RQLQuery().asset.id, method)(("first", "second", third))
+    rexpr_list = getattr(RQLQuery().asset.id, method)(["first", "second", third])
 
     with pytest.raises(TypeError):
         getattr(RQLQuery().asset.id, method)("Test")
 
-    assert str(rexpr_set) == f"{op}(asset.id,(first,second))"
-    assert str(rexpr_list) == f"{op}(asset.id,(first,second))"
+    assert str(rexpr_set) == f"{op}(asset.id,('first','second',third))"
+    assert str(rexpr_list) == f"{op}(asset.id,('first','second',third))"
 
 
 @pytest.mark.parametrize(
diff --git a/tests/unit/rql/query_builder/test_rql_in.py b/tests/unit/rql/query_builder/test_rql_in.py
index 196fb6d6..3deda1db 100644
--- a/tests/unit/rql/query_builder/test_rql_in.py
+++ b/tests/unit/rql/query_builder/test_rql_in.py
@@ -1,4 +1,4 @@
-from mpt_api_client.rql import RQLQuery
+from mpt_api_client.rql import Property, RQLQuery
 
 
 def test_in_and_namespaces():
@@ -11,9 +11,8 @@ def test_in_and_namespaces():
 
 
 def test_in():
-    products = ["PRD-1", "PRD-2"]
-    product_ids = ",".join(products)
+    products = ["PRD-1", "PRD-2", Property("product.id")]
 
     result = RQLQuery(product__id__in=products)
 
-    assert str(result) == f"in(product.id,({product_ids}))"
+    assert str(result) == "in(product.id,('PRD-1','PRD-2',product.id))"
diff --git a/tests/unit/rql/query_builder/test_rql_parse_kwargs.py b/tests/unit/rql/query_builder/test_rql_parse_kwargs.py
index b6160eb6..6aae7453 100644
--- a/tests/unit/rql/query_builder/test_rql_parse_kwargs.py
+++ b/tests/unit/rql/query_builder/test_rql_parse_kwargs.py
@@ -18,7 +18,7 @@ def test_improper_op(mock_product_id_for_expression):
 
     result = parse_kwargs(products_expr)
 
-    assert str(result) == f"['eq(product.id.inn,{mock_product_id_for_expression})']"
+    assert str(result) == "[\"eq(product.id.inn,'PRD-1')\"]"
 
 
 def test_parse_eq(mock_product_id_for_expression):
@@ -26,7 +26,7 @@ def test_parse_eq(mock_product_id_for_expression):
 
     result = parse_kwargs(products_expr)
 
-    assert str(result) == f"['eq(product.id,{mock_product_id_for_expression})']"
+    assert str(result) == "[\"eq(product.id,'PRD-1')\"]"
 
 
 def test_parse_like(mock_product_id_for_expression):
@@ -34,7 +34,7 @@ def test_parse_like(mock_product_id_for_expression):
 
     result = parse_kwargs(products_expr)
 
-    assert str(result) == f"['like(product.id,{mock_product_id_for_expression})']"
+    assert str(result) == "[\"like(product.id,'PRD-1')\"]"
 
 
 def test_parse_null_op(mock_product_id_for_expression):