diff --git a/plugins/system/cpu_linux_multi b/plugins/system/cpu_linux_multi
index 63fe9591..f96b719c 100755
--- a/plugins/system/cpu_linux_multi
+++ b/plugins/system/cpu_linux_multi
@@ -148,7 +148,7 @@ sub graph_section() { "system:cpu" };
 sub graph_name() { "cpu_extended_multi_1s" };
 sub graph_title() { "CPU usage" };
 sub graph_title_all() { "Overall CPU usage" };
-sub graph_title_n($) { "CPU#" . shift . " usage" };
+sub graph_title_n($) { "CPU#" . (shift) . " usage" };
 sub acquire_name() { "<$plugin> collecting information" }
 
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