diff --git a/src/ragger/conftest/base_conftest.py b/src/ragger/conftest/base_conftest.py
index a9267116..2b00f281 100644
--- a/src/ragger/conftest/base_conftest.py
+++ b/src/ragger/conftest/base_conftest.py
@@ -118,7 +118,19 @@ def prepare_speculos_args(root_pytest_dir: Path, firmware: Firmware, display: bo
     project_root_dir = find_project_root_dir(root_pytest_dir)
 
     # Find the standalone application for the requested device
-    app_path = find_main_application(project_root_dir / conf.OPTIONAL.APP_DIR, device)
+    # If the app is to be loaded as a library, the main app should be located in a subfolder of
+    # project_root_dir / conf.OPTIONAL.APP_DIR. There should be only one subfolder in the path.
+    app_path = None
+    if conf.OPTIONAL.LOAD_MAIN_APP_AS_LIBRARY:
+        app_dir_children = list((project_root_dir / conf.OPTIONAL.APP_DIR).iterdir())
+        if len(app_dir_children) != 1:
+            raise ValueError(
+                f"Expected a single folder in {conf.OPTIONAL.APP_DIR}, found {len(app_dir_children)}"
+            )
+        app_path = find_main_application(app_dir_children[0], device)
+    # If the app is standalone, the main app should be located in project_root_dir / conf.OPTIONAL.APP_DIR
+    else:
+        app_path = find_main_application(project_root_dir / conf.OPTIONAL.APP_DIR, device)
 
     # Find all libraries that have to be sideloaded
     if conf.OPTIONAL.LOAD_MAIN_APP_AS_LIBRARY:
diff --git a/tests/unit/conftests/test_base_conftest.py b/tests/unit/conftests/test_base_conftest.py
index 453216b8..ddd0d275 100644
--- a/tests/unit/conftests/test_base_conftest.py
+++ b/tests/unit/conftests/test_base_conftest.py
@@ -1,4 +1,5 @@
 from pathlib import Path
+from typing import Tuple
 from unittest import TestCase
 from unittest.mock import patch
 
@@ -8,12 +9,15 @@
 from ..helpers import temporary_directory
 
 
-def prepare_base_dir(directory: Path) -> Path:
+def prepare_base_dir(directory: Path) -> Tuple[Path, Path]:
     (directory / ".git").mkdir()
     (directory / "build" / "stax" / "bin").mkdir(parents=True, exist_ok=True)
+    (directory / "deps" / "dep" / "build" / "stax" / "bin").mkdir(parents=True, exist_ok=True)
+    dep_path = (directory / "deps" / "dep" / "build" / "stax" / "bin" / "app.elf")
+    dep_path.touch()
     app_path = (directory / "build" / "stax" / "bin" / "app.elf")
     app_path.touch()
-    return app_path
+    return app_path, dep_path
 
 
 class TestBaseConftest(TestCase):
@@ -23,7 +27,7 @@ def setUp(self):
 
     def test_prepare_speculos_args_simplest(self):
         with temporary_directory() as temp_dir:
-            app_path = prepare_base_dir(temp_dir)
+            app_path, _ = prepare_base_dir(temp_dir)
             result_app, result_args = bc.prepare_speculos_args(temp_dir, Firmware.STAX, False,
                                                                self.seed)
             self.assertEqual(result_app, app_path)
@@ -31,7 +35,7 @@ def test_prepare_speculos_args_simplest(self):
 
     def test_prepare_speculos_args_simple_with_gui(self):
         with temporary_directory() as temp_dir:
-            app_path = prepare_base_dir(temp_dir)
+            app_path, _ = prepare_base_dir(temp_dir)
             result_app, result_args = bc.prepare_speculos_args(temp_dir, Firmware.STAX, True,
                                                                self.seed)
             self.assertEqual(result_app, app_path)
@@ -39,12 +43,13 @@ def test_prepare_speculos_args_simple_with_gui(self):
 
     def test_prepare_speculos_args_main_as_library(self):
         with temporary_directory() as temp_dir:
-            app_path = prepare_base_dir(temp_dir)
+            app_path, dep_path = prepare_base_dir(temp_dir)
             with patch("ragger.conftest.base_conftest.conf.OPTIONAL.LOAD_MAIN_APP_AS_LIBRARY",
                        True):
-                result_app, result_args = bc.prepare_speculos_args(temp_dir, Firmware.STAX, False,
-                                                                   self.seed)
-                self.assertEqual(result_app, app_path)
+                with patch("ragger.conftest.base_conftest.conf.OPTIONAL.APP_DIR", "deps"):
+                    result_app, result_args = bc.prepare_speculos_args(
+                        temp_dir, Firmware.STAX, False, self.seed)
+                self.assertEqual(result_app, dep_path)
                 self.assertEqual(result_args, {"args": [f"-l{app_path}", "--seed", self.seed]})
 
     def test_prepare_speculos_args_sideloaded_apps_nok_no_dir(self):
@@ -58,7 +63,7 @@ def test_prepare_speculos_args_sideloaded_apps_nok_no_dir(self):
     def test_prepare_speculos_args_sideloaded_apps_ok(self):
         lib1_bin, lib1_name, lib2_bin, lib2_name = "lib1", "name1", "lib2", "name2"
         with temporary_directory() as temp_dir:
-            app_path = prepare_base_dir(temp_dir)
+            app_path, _ = prepare_base_dir(temp_dir)
             sideloaded_apps_dir = temp_dir / "here"
             sideloaded_apps_dir.mkdir()
             lib1_path = sideloaded_apps_dir / f"{lib1_bin}_stax.elf"