diff --git a/acbs/base.py b/acbs/base.py
index 7c9ba95..02c152e 100644
--- a/acbs/base.py
+++ b/acbs/base.py
@@ -47,6 +47,12 @@ def __init__(self, name: str, deps: List[str], location: str, source_uri: List[A
         self.script_location = location
         # extra exported variables from spec
         self.exported: Dict[str, str] = {}
+        # modifiers to be applied to the source file/folder (only available in autobuild4)
+        self.modifiers: str = ''
+
+    def is_in_stage2(modifiers: str) -> bool:
+        return '+stage2' in modifiers.lower()
+
 
     def __repr__(self) -> str:
         return f'<ACBSPackageInfo {self.name}: deps: {self.deps} ; uri: {self.source_uri}>'
diff --git a/acbs/main.py b/acbs/main.py
index 9463dfe..dd29ee2 100644
--- a/acbs/main.py
+++ b/acbs/main.py
@@ -93,15 +93,13 @@ def __install_logger(self, str_verbosity=logging.INFO,
             '%(asctime)s:%(levelname)s:%(message)s'))
         logger.addHandler(log_file_handler)
 
-    def set_modifiers(self, p: str) -> str:
-        del os.environ['ABMODIFIERS']
+    def strip_modifiers(self, p: str) -> Tuple[str, str]:
         if ':' in p:
             results = p.split(':', 1)
             if len(p) == 2:
                 p, m = results
-                os.environ['ABMODIFIERS'] = m
-                return p
-        return p
+                return p, m
+        return p, ''
 
     def build(self) -> None:
         packages = []
@@ -114,12 +112,13 @@ def build(self) -> None:
         logging.info('Searching and resolving dependencies...')
         acbs.pm.reorder_mode = self.reorder
         for n, i in enumerate(self.build_queue):
-            i = self.set_modifiers(i)
+            i, modifiers = self.set_modifiers(i)
             if not validate_package_name(i):
                 raise ValueError(f'Invalid package name: `{i}`')
             logging.debug(f'Finding {i}...')
             print(f'[{n + 1}/{len(self.build_queue)}] {i:30}\r', end='', flush=True)
-            package = find_package(i, self.tree_dir, stage2=self.stage2)
+            scoped_stage2 = ACBSPackageInfo.is_in_stage2(modifiers) | self.stage2
+            package = find_package(i, self.tree_dir, stage2=scoped_stage2)
             if not package:
                 raise RuntimeError(f'Could not find package {i}')
             packages.extend(package)
@@ -268,7 +267,8 @@ def build_sequential(self, build_timings, packages: List[ACBSPackageInfo]):
             start = time.monotonic()
             task_name = f'{task.name} ({task.bin_arch} @ {task.epoch + ":" if task.epoch else ""}{task.version}-{task.rel})'
             try:
-                invoke_autobuild(task, build_dir, self.stage2)
+                scoped_stage2 = ACBSPackageInfo.is_in_stage2(task.modifiers) | stage2
+                invoke_autobuild(task, build_dir, scoped_stage2)
                 check_artifact(task.name, build_dir)
             except Exception:
                 # early printing of build summary before exploding
diff --git a/acbs/utils.py b/acbs/utils.py
index a085181..02c9c46 100644
--- a/acbs/utils.py
+++ b/acbs/utils.py
@@ -199,6 +199,8 @@ def invoke_autobuild(task: ACBSPackageInfo, build_dir: str, stage2: bool):
     env_dict.update({'PKGREL': task.rel, 'PKGVER': task.version,
                      'PKGEPOCH': task.epoch or '0'})
     env_dict.update(task.exported)
+    if task.modifiers:
+        env_dict['ABMODIFIERS'] = task.modifiers
     defines_file = 'defines'
     if stage2 and os.path.exists(os.path.join(build_dir, 'autobuild', 'defines.stage2')):
         defines_file = 'defines.stage2'