diff --git a/colin/core/ruleset/ruleset.py b/colin/core/ruleset/ruleset.py
index 89a300f..ba52a4a 100644
--- a/colin/core/ruleset/ruleset.py
+++ b/colin/core/ruleset/ruleset.py
@@ -216,11 +216,17 @@ def get_ruleset_dirs():
         logger.debug("Local ruleset directory found ('%s').", local_share)
         ruleset_dirs.append(local_share)
 
-    usr_local_share = os.path.join(sys.prefix, RULESET_DIRECTORY)
+    usr_local_share = os.path.join("/usr/local", RULESET_DIRECTORY)
     if os.path.isdir(usr_local_share):
         logger.debug("Global ruleset directory found ('%s').", usr_local_share)
         ruleset_dirs.append(usr_local_share)
 
+    if sys.prefix != "/usr/local":
+        global_share = os.path.join(sys.prefix, RULESET_DIRECTORY)
+        if os.path.isdir(global_share):
+            logger.debug("Global ruleset directory found ('%s').", global_share)
+            ruleset_dirs.append(global_share)
+
     if not ruleset_dirs:
         msg = "Ruleset directory cannot be found."
         logger.warning(msg)
diff --git a/docs/list_of_checks.rst b/docs/list_of_checks.rst
index adaa620..f15ae01 100644
--- a/docs/list_of_checks.rst
+++ b/docs/list_of_checks.rst
@@ -49,6 +49,7 @@ Colin can use ruleset-files in the following directories:
 
 - ``./rulesets/`` (subdirectory of the current working directory)
 - ``~/.local/share/colin/rulesets/`` (user installation)
+- ``/usr/local/share/colin/rulesets/`` (system-wide installation if `sys.prefix` is not `/usr/local`)
 - `sys.prefix`_\ ``/share/colin/rulesets/`` (system-wide installation)
 
 .. _sys.prefix: https://docs.python.org/3/library/sys.html?highlight=sys%20prefix#sys.prefix