diff --git a/EqSat/include/Luau/EGraph.h b/EqSat/include/Luau/EGraph.h
index 6029b18f..3a18a361 100644
--- a/EqSat/include/Luau/EGraph.h
+++ b/EqSat/include/Luau/EGraph.h
@@ -39,7 +39,7 @@ struct Analysis final
         return tableMake[enode.index()](analysis, egraph, enode);
     }
 
-    void join(D& a, const D& b)
+    void join(D& a, const D& b) const
     {
         return analysis.join(a, b);
     }
diff --git a/tests/EqSat.propositional.test.cpp b/tests/EqSat.propositional.test.cpp
index 5e019adc..47a35cac 100644
--- a/tests/EqSat.propositional.test.cpp
+++ b/tests/EqSat.propositional.test.cpp
@@ -81,7 +81,7 @@ struct ConstantFold
         return std::nullopt;
     }
 
-    void join(Data& a, const Data& b)
+    void join(Data& a, const Data& b) const
     {
         if (!a && b)
             a = b;