diff --git a/bin/tests/system/.gitignore b/bin/tests/system/.gitignore
index e2daf1cef5..d26b4b0d3d 100644
--- a/bin/tests/system/.gitignore
+++ b/bin/tests/system/.gitignore
@@ -26,3 +26,4 @@ named.run
 /*_*
 !/*_*.py
 !/*_*.sh
+!/_common
diff --git a/bin/tests/system/Makefile.am b/bin/tests/system/Makefile.am
index 44282372de..3607451e4e 100644
--- a/bin/tests/system/Makefile.am
+++ b/bin/tests/system/Makefile.am
@@ -240,4 +240,4 @@ $(TESTS): legacy.run.sh
 test-local: check
 
 clean-local::
-	-find $(builddir) -maxdepth 1 -type d -name "*_*" | xargs rm -rf
+	-find -L . -mindepth 1 -maxdepth 1 -type d -name "*_*" -and -not -name "_common" -exec rm -rf {} \;