diff --git a/src/kernel_services/ast_queries/ast_diff.ml b/src/kernel_services/ast_queries/ast_diff.ml
index e8173fb6c8e31d4466e521ae18d9782b50903745..ce895a7c9d6b847526fa17d0d7bd65fe6a839d91 100644
--- a/src/kernel_services/ast_queries/ast_diff.ml
+++ b/src/kernel_services/ast_queries/ast_diff.ml
@@ -568,7 +568,7 @@ and is_same_term_node t t' env =
   | TSizeOfStr s, TSizeOfStr s' -> String.length s = String.length s'
   | TUnOp(op,t), TUnOp(op',t') -> Unop.equal op op' && is_same_term t t' env
   | TBinOp(op,t1,t2), TBinOp(op',t1',t2') ->
-    Binop.equal op op' && is_same_term t1 t2 env && is_same_term t1' t2' env
+    Binop.equal op op' && is_same_term t1 t1' env && is_same_term t2 t2' env
   | TCastE(typ,term), TCastE(typ',term') ->
     is_same_type typ typ' env && is_same_term term term' env
   | TAddrOf lv, TAddrOf lv'