diff --git a/mythril/analysis/security.py b/mythril/analysis/security.py
index 5c5e520a..4d95497a 100644
--- a/mythril/analysis/security.py
+++ b/mythril/analysis/security.py
@@ -65,38 +65,36 @@ def get_detection_modules(entrypoint, include_modules=(), custom_modules_directo
 
     _modules = []
 
-    for loader, module_name, _ in pkgutil.walk_packages(modules.__path__):
+    custom_modules_directory = os.path.abspath(custom_modules_directory)
+
+    if custom_modules_directory and custom_modules_directory not in sys.path:
+        sys.path.append(custom_modules_directory)
+
+    custom_packages = (
+        list(pkgutil.walk_packages([custom_modules_directory]))
+        if custom_modules_directory
+        else []
+    )
+    packages = list(pkgutil.walk_packages(modules.__path__)) + custom_packages
+
+    for loader, module_name, _ in packages:
         if include_modules and module_name not in include_modules:
             continue
 
         if module_name != "base":
-            module = importlib.import_module("mythril.analysis.modules." + module_name)
+            try:
+                module = importlib.import_module(
+                    "mythril.analysis.modules." + module_name
+                )
+            except ModuleNotFoundError:
+                try:
+                    module = importlib.import_module(module_name)
+                except ModuleNotFoundError:
+                    raise ModuleNotFoundError
             module.log.setLevel(log.level)
             if module.detector.entrypoint == entrypoint:
                 _modules.append(module)
-    if custom_modules_directory:
-        custom_modules = [os.path.abspath(custom_modules_directory)]
-        sys.path.append(custom_modules_directory)
 
-        for loader, module_name, _ in pkgutil.walk_packages(custom_modules):
-            if include_modules and module_name not in include_modules:
-                continue
-
-            if module_name != "base":
-                module = importlib.import_module(module_name, custom_modules[0])
-                module.log.setLevel(log.level)
-                if module.detector.entrypoint == entrypoint:
-                    _modules.append(module)
-
-    """
-    for loader, module_name, _ in pkgutil.walk_packages([custom_modules_path]):
-
-    custom_modules_path = os.path.abspath("custom/")
-    sys.path.append(custom_modules_path);
-    module = importlib.import_module(
-        module_name, custom_modules_path
-    )
-    """
     log.info("Found %s detection modules", len(_modules))
     return _modules