diff --git a/doc/changelog/04-tactics/17704-open-constr-no-expand.rst b/doc/changelog/04-tactics/17704-open-constr-no-expand.rst
new file mode 100644
index 000000000000..de4482c988f5
--- /dev/null
+++ b/doc/changelog/04-tactics/17704-open-constr-no-expand.rst
@@ -0,0 +1,6 @@
+- **Changed:**
+  `open_constr` in Ltac1 and Ltac2 does not perform evar normalization.
+  Normalization may be recovered using `let c := open_constr:(...) in constr:(c)`
+  if necessary for performance
+  (`#17704 <https://github.com/coq/coq/pull/17704>`_,
+  by Gaëtan Gilbert).
diff --git a/plugins/ltac/tacinterp.ml b/plugins/ltac/tacinterp.ml
index 595a4e21309c..b1b05e4a7e6f 100644
--- a/plugins/ltac/tacinterp.ml
+++ b/plugins/ltac/tacinterp.ml
@@ -632,7 +632,7 @@ let open_constr_use_classes_flags () = {
   use_typeclasses = UseTC;
   solve_unification_constraints = true;
   fail_evar = false;
-  expand_evars = true;
+  expand_evars = false;
   program_mode = false;
   polymorphic = false;
 }
@@ -642,7 +642,7 @@ let open_constr_no_classes_flags () = {
   use_typeclasses = NoUseTC;
   solve_unification_constraints = true;
   fail_evar = false;
-  expand_evars = true;
+  expand_evars = false;
   program_mode = false;
   polymorphic = false;
 }
diff --git a/plugins/ltac2/tac2core.ml b/plugins/ltac2/tac2core.ml
index d70a4daac55a..478676239dcd 100644
--- a/plugins/ltac2/tac2core.ml
+++ b/plugins/ltac2/tac2core.ml
@@ -39,7 +39,7 @@ let open_constr_no_classes_flags =
   use_typeclasses = Pretyping.NoUseTC;
   solve_unification_constraints = true;
   fail_evar = false;
-  expand_evars = true;
+  expand_evars = false;
   program_mode = false;
   polymorphic = false;
   }