diff --git a/ChangeLog b/ChangeLog
index 9dae0f4356..7c81884ff1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -12,6 +12,11 @@ What's New in astroid 2.12.5?
 =============================
 Release date: TBA
 
+
+* Prevent first-party imports from being resolved to `site-packages`.
+
+  Refs PyCQA/pylint#7365
+
 * Fix ``astroid.interpreter._import.util.is_namespace()`` incorrectly
   returning ``True`` for frozen stdlib modules on PyPy.
 
diff --git a/astroid/interpreter/_import/util.py b/astroid/interpreter/_import/util.py
index 0c29d670ef..8cdb8ea19d 100644
--- a/astroid/interpreter/_import/util.py
+++ b/astroid/interpreter/_import/util.py
@@ -15,6 +15,13 @@
 
 @lru_cache(maxsize=4096)
 def is_namespace(modname: str) -> bool:
+    from astroid.modutils import (  # pylint: disable=import-outside-toplevel
+        EXT_LIB_DIRS,
+        STD_LIB_DIRS,
+    )
+
+    STD_AND_EXT_LIB_DIRS = STD_LIB_DIRS.union(EXT_LIB_DIRS)
+
     if modname in sys.builtin_module_names:
         return False
 
@@ -72,8 +79,15 @@ def is_namespace(modname: str) -> bool:
                 last_submodule_search_locations.append(str(assumed_location))
             continue
 
-        # Update last_submodule_search_locations
+        # Update last_submodule_search_locations for next iteration
         if found_spec and found_spec.submodule_search_locations:
+            # But immediately return False if we can detect we are in stdlib
+            # or external lib (e.g site-packages)
+            if any(
+                any(location.startswith(lib_dir) for lib_dir in STD_AND_EXT_LIB_DIRS)
+                for location in found_spec.submodule_search_locations
+            ):
+                return False
             last_submodule_search_locations = found_spec.submodule_search_locations
 
     return (
diff --git a/tests/unittest_manager.py b/tests/unittest_manager.py
index 79f21db138..6c13da787d 100644
--- a/tests/unittest_manager.py
+++ b/tests/unittest_manager.py
@@ -17,7 +17,7 @@
 from astroid.const import IS_JYTHON, IS_PYPY
 from astroid.exceptions import AstroidBuildingError, AstroidImportError
 from astroid.interpreter._import import util
-from astroid.modutils import is_standard_module
+from astroid.modutils import EXT_LIB_DIRS, is_standard_module
 from astroid.nodes import Const
 from astroid.nodes.scoped_nodes import ClassDef
 
@@ -130,6 +130,9 @@ def test_submodule_homonym_with_non_module(self) -> None:
     def test_module_is_not_namespace(self) -> None:
         self.assertFalse(util.is_namespace("tests.testdata.python3.data.all"))
         self.assertFalse(util.is_namespace("__main__"))
+        self.assertFalse(
+            util.is_namespace(list(EXT_LIB_DIRS)[0].rsplit("/", maxsplit=1)[-1]),
+        )
         self.assertFalse(util.is_namespace("importlib._bootstrap"))
 
     def test_module_unexpectedly_missing_spec(self) -> None: