diff --git a/src/emu/model.c b/src/emu/model.c
index f750784..8e5a96e 100644
--- a/src/emu/model.c
+++ b/src/emu/model.c
@@ -235,13 +235,6 @@ model_finish(struct model *model, struct emu *emu)
 static int
 should_enable(int have[3], struct model_spec *spec, struct thread *t)
 {
-	static int compat = 0;
-
-	/* Enable all models if we are in compatibility model. Don't check other
-	 * threads metadata */
-	if (compat)
-		return 1;
-
 	if (t->meta == NULL) {
 		err("missing metadata for thread %s", t->id);
 		return -1;
@@ -249,12 +242,8 @@ should_enable(int have[3], struct model_spec *spec, struct thread *t)
 
 	JSON_Object *require = json_object_dotget_object(t->meta, "ovni.require");
 	if (require == NULL) {
-		warn("missing 'ovni.require' key in thread %s", t->id);
-		warn("loading trace in compatibility mode");
-		warn("all models will be enabled (expect slowdown)");
-		warn("use ovni_thread_require() to enable only required models");
-		compat = 1;
-		return 1;
+		err("missing 'ovni.require' key in thread %s", t->id);
+		return -1;
 	}
 
 	/* May not have the current model */
diff --git a/test/emu/ovni/CMakeLists.txt b/test/emu/ovni/CMakeLists.txt
index d01eb2d..d62ec34 100644
--- a/test/emu/ovni/CMakeLists.txt
+++ b/test/emu/ovni/CMakeLists.txt
@@ -21,7 +21,7 @@ test_emu(sort-cpus-by-rank.c MP)
 test_emu(tracedir-subdir.c MP DRIVER "tracedir-subdir.driver.sh")
 test_emu(empty-stream.c SHOULD_FAIL REGEX "missing ovni.finished")
 test_emu(require-bad-version.c SHOULD_FAIL REGEX "unsupported ovni model version (want 666.66.6, have .*)")
-test_emu(require-compat.c REGEX "loading trace in compatibility mode")
+test_emu(require-compat.c SHOULD_FAIL REGEX "missing 'ovni.require' key in thread")
 test_emu(require-repeated.c)
 test_emu(thread-crash.c SHOULD_FAIL REGEX "missing ovni.finished")
 test_emu(thread-free-isready.c)
diff --git a/test/emu/ovni/sort-cpus-by-loom.c b/test/emu/ovni/sort-cpus-by-loom.c
index 7fe4f3f..c143a57 100644
--- a/test/emu/ovni/sort-cpus-by-loom.c
+++ b/test/emu/ovni/sort-cpus-by-loom.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2023 Barcelona Supercomputing Center (BSC)
+/* Copyright (c) 2023-2024 Barcelona Supercomputing Center (BSC)
  * SPDX-License-Identifier: GPL-3.0-or-later */
 
 #include <stdio.h>
@@ -35,6 +35,7 @@ main(void)
 	for (int i = 0; i < N; i++)
 		ovni_add_cpu(i, cpus[i]);
 
+	instr_require("ovni");
 	instr_thread_execute(-1, -1, 0);
 
 	instr_end();
diff --git a/test/emu/ovni/sort-cpus-by-rank.c b/test/emu/ovni/sort-cpus-by-rank.c
index b919cb7..ecb036e 100644
--- a/test/emu/ovni/sort-cpus-by-rank.c
+++ b/test/emu/ovni/sort-cpus-by-rank.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2023 Barcelona Supercomputing Center (BSC)
+/* Copyright (c) 2023-2024 Barcelona Supercomputing Center (BSC)
  * SPDX-License-Identifier: GPL-3.0-or-later */
 
 #include <stdio.h>
@@ -36,6 +36,7 @@ main(void)
 	for (int i = 0; i < N; i++)
 		ovni_add_cpu(i, cpus[i]);
 
+	instr_require("ovni");
 	instr_thread_execute(-1, -1, 0);
 
 	instr_end();