diff --git a/SConstruct b/SConstruct
index 81ef3b0ae9..40aa3bc063 100644
--- a/SConstruct
+++ b/SConstruct
@@ -295,7 +295,12 @@ for path in module_search_paths:
         # from the built-in "modules" name (e.g. "custom_modules/summator/summator.h"),
         # so it can be referenced simply as `#include "summator/summator.h"`
         # independently of where a module is located on user's filesystem.
-        env_base.Prepend(CPPPATH=[path, os.path.dirname(path)])
+
+        if not os.path.isabs(path):
+            env_base.Prepend(CPPPATH=["#" + path, "#" + os.path.dirname(path)])
+        else:
+            env_base.Prepend(CPPPATH=[path, os.path.dirname(path)])
+            
     # Note: custom modules can override built-in ones.
     modules_detected.update(modules)
 
diff --git a/methods.py b/methods.py
index 2828d5dfa4..6ae22a84fd 100644
--- a/methods.py
+++ b/methods.py
@@ -439,7 +439,7 @@ def convert_custom_modules_path(path):
     if path == os.path.realpath("modules"):
         raise ValueError(err_msg % "be a directory other than built-in `modules` directory.")
     
-    current_path = os.path.realpath(".")
+    current_path = os.path.realpath(".") + "/"
 
     if path.startswith(current_path):
         path = path.replace(current_path, "", 1)
diff --git a/modules/SCsub b/modules/SCsub
index 678a614c95..133dd5ca1d 100644
--- a/modules/SCsub
+++ b/modules/SCsub
@@ -17,8 +17,12 @@ env.modules_sources = []
 env_modules.add_source_files(env.modules_sources, "register_module_types.gen.cpp")
 
 for name, path in env.module_list.items():
+
     if not os.path.isabs(path):
-        SConscript(name + "/SCsub")  # Built-in.
+        if path.startswith("modules/"):
+            SConscript(name + "/SCsub")  # Built-in.
+        else:
+            SConscript("../" + path + "/SCsub")  # In the engine's folder, so start from there
     else:
         SConscript(path + "/SCsub")  # Custom.