diff --git a/src/rpy2/rinterface_lib/embedded.py b/src/rpy2/rinterface_lib/embedded.py
index cc9f7da1..10626f13 100644
--- a/src/rpy2/rinterface_lib/embedded.py b/src/rpy2/rinterface_lib/embedded.py
@@ -328,6 +328,15 @@ def _initr(
             _setinitialized()
             return None
 
+        # path to libraries
+        existing = os.environ.get('R_LIBS_SITE')
+        if existing is not None:
+            prefix = existing + ':'
+        else:
+            prefix = ''
+        additional = '@NIX_R_LIBS_SITE@'
+        os.environ['R_LIBS_SITE'] = prefix + additional
+
         # TODO: Setting LD_LIBRARY_PATH after the process has started
         # is too late. Because of this, the line below does not help
         # address issues where calling R from the command line is working