diff --git b/src/nrpe.c a/src/nrpe.c
index 381f0ac..ad1e05d 100644
--- b/src/nrpe.c
+++ a/src/nrpe.c
@@ -53,7 +53,7 @@ int use_ssl=FALSE;
#define DEFAULT_COMMAND_TIMEOUT 60 /* default timeout for execution of plugins */
#define MAXFD 64
-#define NASTY_METACHARS "|`&><'\"\\[]{};"
+#define NASTY_METACHARS "|`&><'\"\\[]{};\n"
#define howmany(x,y) (((x)+((y)-1))/(y))
#define MAX_LISTEN_SOCKS 16