diff --git a/src/cgutil.c b/src/cgutil.c
index 04901053..34af0eab 100644
--- a/src/cgutil.c
+++ b/src/cgutil.c
@@ -102,6 +102,7 @@ char *pid_cmdline(int pid)
 			buf[i] = ' ';
 	}
 
+	fclose(fp);
 	return buf;
 }