diff --git a/CHANGES.md b/CHANGES.md
index cc070f1bd4c..12ebde9445d 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -25,6 +25,8 @@
 - Allow rules producing directory targets to create symlinks (#6077, fixes
   #5945, @rgrinberg)
 
+- Inline tests are now sandboxed by default (#6079, @rgrinberg)
+
 3.4.1 (26-07-2022)
 ------------------
 
diff --git a/src/dune_rules/dep_conf_eval.ml b/src/dune_rules/dep_conf_eval.ml
index 5e923738700..cc0bad4483e 100644
--- a/src/dune_rules/dep_conf_eval.ml
+++ b/src/dune_rules/dep_conf_eval.ml
@@ -290,11 +290,10 @@ let named ~expander l =
         | Unnamed dep -> add_sandbox_config acc dep
         | Named (_, l) -> List.fold_left l ~init:acc ~f:add_sandbox_config) )
 
-let unnamed ~expander l =
+let unnamed ?(sandbox = Sandbox_config.no_special_requirements) ~expander l =
   let expander = prepare_expander expander in
   ( List.fold_left l ~init:(Action_builder.return ()) ~f:(fun acc x ->
         let+ () = acc
         and+ _x = to_action_builder (dep expander x) in
         ())
-  , List.fold_left l ~init:Sandbox_config.no_special_requirements
-      ~f:add_sandbox_config )
+  , List.fold_left l ~init:sandbox ~f:add_sandbox_config )
diff --git a/src/dune_rules/dep_conf_eval.mli b/src/dune_rules/dep_conf_eval.mli
index e0028dceea4..0e88037dc91 100644
--- a/src/dune_rules/dep_conf_eval.mli
+++ b/src/dune_rules/dep_conf_eval.mli
@@ -7,7 +7,8 @@ val package_install : context:Build_context.t -> pkg:Package.t -> Alias.t
 
 (** Evaluates unnamed dependency specifications. *)
 val unnamed :
-     expander:Expander.t
+     ?sandbox:Sandbox_config.t
+  -> expander:Expander.t
   -> Dep_conf.t list
   -> unit Action_builder.t * Sandbox_config.t
 
diff --git a/src/dune_rules/inline_tests.ml b/src/dune_rules/inline_tests.ml
index 30c4d1ac94a..a926e197acf 100644
--- a/src/dune_rules/inline_tests.ml
+++ b/src/dune_rules/inline_tests.ml
@@ -229,7 +229,15 @@ include Sub_system.Register_end_point (struct
              Path.build (Path.Build.relative inline_test_dir (name ^ ext))
            in
            let open Action_builder.O in
-           let deps, sandbox = Dep_conf_eval.unnamed info.deps ~expander in
+           let deps, sandbox =
+             let sandbox =
+               let project = Scope.project scope in
+               if Dune_project.dune_version project < (3, 5) then
+                 Sandbox_config.no_special_requirements
+               else Sandbox_config.needs_sandboxing
+             in
+             Dep_conf_eval.unnamed ~sandbox info.deps ~expander
+           in
            let+ () = deps
            and+ () = Action_builder.paths source_files
            and+ () = Action_builder.path exe