diff --git a/sdks/julia/LogicalQueryProtocol.jl/src/equality.jl b/sdks/julia/LogicalQueryProtocol.jl/src/equality.jl
index 39c46cb8..5dea98e8 100644
--- a/sdks/julia/LogicalQueryProtocol.jl/src/equality.jl
+++ b/sdks/julia/LogicalQueryProtocol.jl/src/equality.jl
@@ -607,9 +607,9 @@ Base.hash(a::CDCTargets, h::UInt) = hash(a.deletes, hash(a.inserts, h))
 Base.isequal(a::CDCTargets, b::CDCTargets) = isequal(a.inserts, b.inserts) && isequal(a.deletes, b.deletes)
 
 # TargetRelations
-Base.:(==)(a::TargetRelations, b::TargetRelations) = a.keys == b.keys && _isequal_oneof(a.body, b.body)
-Base.hash(a::TargetRelations, h::UInt) = _hash_oneof(a.body, hash(a.keys, h))
-Base.isequal(a::TargetRelations, b::TargetRelations) = isequal(a.keys, b.keys) && _isequal_oneof(a.body, b.body)
+Base.:(==)(a::TargetRelations, b::TargetRelations) = a.keys == b.keys && a.synthetic_key == b.synthetic_key && _isequal_oneof(a.body, b.body)
+Base.hash(a::TargetRelations, h::UInt) = _hash_oneof(a.body, hash(a.synthetic_key, hash(a.keys, h)))
+Base.isequal(a::TargetRelations, b::TargetRelations) = isequal(a.keys, b.keys) && isequal(a.synthetic_key, b.synthetic_key) && _isequal_oneof(a.body, b.body)
 
 # CSVData
 Base.:(==)(a::CSVData, b::CSVData) = a.locator == b.locator && a.config == b.config && a.columns == b.columns && a.asof == b.asof && a.relations == b.relations
diff --git a/sdks/julia/LogicalQueryProtocol.jl/test/equality_tests.jl b/sdks/julia/LogicalQueryProtocol.jl/test/equality_tests.jl
index b48cbed6..98f0b542 100644
--- a/sdks/julia/LogicalQueryProtocol.jl/test/equality_tests.jl
+++ b/sdks/julia/LogicalQueryProtocol.jl/test/equality_tests.jl
@@ -2339,6 +2339,14 @@ end
 
     # Different oneof arms are unequal even when they share a relation.
     @test g1 != cdc1
+
+    # `synthetic_key` participates in equality and hashing.
+    s1 = TargetRelations(keys=[], body=plain([rel1]), synthetic_key=true)
+    s2 = TargetRelations(keys=[], body=plain([rel1]), synthetic_key=true)
+    @test s1 == s2
+    @test hash(s1) == hash(s2)
+    @test isequal(s1, s2)
+    @test s1 != g3   # same keys and body, differs only in synthetic_key
 end
 
 @testitem "Equality for CSVData" tags=[:ring1, :unit] begin