diff --git a/langkit/expressions/logic.py b/langkit/expressions/logic.py
index 0362e0683..164d46364 100644
--- a/langkit/expressions/logic.py
+++ b/langkit/expressions/logic.py
@@ -41,7 +41,7 @@ class Bind(AbstractExpression):
         Bind(A, B, property)
     """
 
-    def __init__(self, from_expr, to_expr, conv_prop=None):
+    def __init__(self, from_expr, to_expr, conv_prop=None, eq_prop=None):
         """
         :param AbstractExpression from_expr: An expression resolving to a
             logical variable that is the source of the bind.
diff --git a/testsuite/tests/adalog/custom_bind/support.ads b/testsuite/tests/adalog/custom_bind/support.ads
index 96a366f2e..ef9aa9d63 100644
--- a/testsuite/tests/adalog/custom_bind/support.ads
+++ b/testsuite/tests/adalog/custom_bind/support.ads
@@ -2,11 +2,12 @@ with Adalog.Abstract_Relation; use Adalog.Abstract_Relation;
 with Adalog.Main_Support;      use Adalog.Main_Support;
 
 package Support is
+   function Eq (A, B : Integer) return Boolean is (A = B);
    type Dummy_Data is null record;
-   D : Dummy_Data;
+   No_Data : constant Dummy_Data := (null record);
 
    function Transform (D : Dummy_Data; I : Integer) return Integer is (I ** 2);
-   package Bind is new Eq_Int.Raw_Custom_Bind (Dummy_Data, Transform);
+   package Bind is new Eq_Int.Raw_Custom_Bind (Dummy_Data, No_Data, Transform, Eq);
    function Square (X, Y : Eq_Int.Refs.Raw_Var) return Relation
-   is (Bind.Create (X, Y, D));
+   is (Bind.Create (X, Y, No_Data));
 end Support;
diff --git a/testsuite/tests/adalog/deferred_predicate/support.ads b/testsuite/tests/adalog/deferred_predicate/support.ads
index 85e4116e7..c071444d3 100644
--- a/testsuite/tests/adalog/deferred_predicate/support.ads
+++ b/testsuite/tests/adalog/deferred_predicate/support.ads
@@ -2,9 +2,11 @@ with Adalog.Main_Support; use Adalog.Main_Support;
 with Adalog.Predicates;   use Adalog.Predicates;
 
 package Support is
+   function Eq (A, B : Integer) return Boolean is (A = B);
    type Dummy_Data is null record;
+   No_Data : constant Dummy_Data := (null record);
    function Transform (D : Dummy_Data; I : Integer) return Integer is (I * 3);
-   package Bind is new Eq_Int.Raw_Custom_Bind (Dummy_Data, Transform);
+   package Bind is new Eq_Int.Raw_Custom_Bind (Dummy_Data, No_Data, Transform, Eq);
 
 
    type Pred is null record;
diff --git a/testsuite/tests/adalog/general/support.ads b/testsuite/tests/adalog/general/support.ads
index 9f49ea5bb..7b564f6ff 100644
--- a/testsuite/tests/adalog/general/support.ads
+++ b/testsuite/tests/adalog/general/support.ads
@@ -1,7 +1,9 @@
 with Adalog.Main_Support;      use Adalog.Main_Support;
 
 package Support is
+   function Eq (A, B : Integer) return Boolean is (A = B);
    type Dummy_Data is null record;
+   No_Data : constant Dummy_Data := (null record);
    function Transform (D : Dummy_Data; I : Integer) return Integer is (I * 3);
-   package Bind is new Eq_Int.Raw_Custom_Bind (Dummy_Data, Transform);
+   package Bind is new Eq_Int.Raw_Custom_Bind (Dummy_Data, No_Data, Transform, Eq);
 end Support;
diff --git a/testsuite/tests/adalog/n_predicate/support.ads b/testsuite/tests/adalog/n_predicate/support.ads
index 049f18f0e..fb4c63405 100644
--- a/testsuite/tests/adalog/n_predicate/support.ads
+++ b/testsuite/tests/adalog/n_predicate/support.ads
@@ -2,9 +2,11 @@ with Adalog.Main_Support; use Adalog.Main_Support;
 with Adalog.Predicates;   use Adalog.Predicates;
 
 package Support is
+   function Eq (A, B : Integer) return Boolean is (A = B);
    type Dummy_Data is null record;
+   No_Data : constant Dummy_Data := (null record);
    function Transform (D : Dummy_Data; I : Integer) return Integer is (I * 3);
-   package Bind is new Eq_Int.Raw_Custom_Bind (Dummy_Data, Transform);
+   package Bind is new Eq_Int.Raw_Custom_Bind (Dummy_Data, No_Data, Transform, Eq);
 
    type Pred is null record;
    function Call (Self : Pred; L, R : Integer) return Boolean is (L = R * 2);
diff --git a/testsuite/tests/adalog/variadics/support.ads b/testsuite/tests/adalog/variadics/support.ads
index 9f49ea5bb..7b564f6ff 100644
--- a/testsuite/tests/adalog/variadics/support.ads
+++ b/testsuite/tests/adalog/variadics/support.ads
@@ -1,7 +1,9 @@
 with Adalog.Main_Support;      use Adalog.Main_Support;
 
 package Support is
+   function Eq (A, B : Integer) return Boolean is (A = B);
    type Dummy_Data is null record;
+   No_Data : constant Dummy_Data := (null record);
    function Transform (D : Dummy_Data; I : Integer) return Integer is (I * 3);
-   package Bind is new Eq_Int.Raw_Custom_Bind (Dummy_Data, Transform);
+   package Bind is new Eq_Int.Raw_Custom_Bind (Dummy_Data, No_Data, Transform, Eq);
 end Support;