diff --git a/plugins/procstat/procstat.go b/plugins/procstat/procstat.go
index 29c7bc1ae..28a221bf5 100644
--- a/plugins/procstat/procstat.go
+++ b/plugins/procstat/procstat.go
@@ -12,7 +12,7 @@ import (
 )
 
 type Specification struct {
-	PidFile string `toml:pid_file`
+	PidFile string `toml:"pid_file"`
 	Exe     string
 	Prefix  string
 }