diff --git a/plugins/check_radius.c b/plugins/check_radius.c
index 8ed19e55..d9ff8fa7 100644
--- a/plugins/check_radius.c
+++ b/plugins/check_radius.c
@@ -46,8 +46,8 @@ const char *email = "devel@monitoring-plugins.org";
 #include <radiusclient.h>
 #endif
 
-int process_arguments (int, char **);
-void print_help (void);
+static int process_arguments (int /*argc*/, char ** /*argv*/);
+static void print_help (void);
 void print_usage (void);
 
 #if defined(HAVE_LIBFREERADIUS_CLIENT) || defined(HAVE_LIBRADIUSCLIENT_NG) || defined(HAVE_LIBRADCLI)
@@ -78,22 +78,22 @@ void print_usage (void);
 #define REJECT_RC BADRESP_RC
 #endif
 
-int my_rc_read_config(char *);
+static int my_rc_read_config(char * /*a*/);
 
 #if defined(HAVE_LIBFREERADIUS_CLIENT) || defined(HAVE_LIBRADIUSCLIENT_NG) || defined(HAVE_LIBRADCLI)
-rc_handle *rch = NULL;
+static rc_handle *rch = NULL;
 #endif
 
-char *server = NULL;
-char *username = NULL;
-char *password = NULL;
-char *nasid = NULL;
-char *nasipaddress = NULL;
-char *expect = NULL;
-char *config_file = NULL;
-unsigned short port = PW_AUTH_UDP_PORT;
-int retries = 1;
-bool verbose = false;
+static char *server = NULL;
+static char *username = NULL;
+static char *password = NULL;
+static char *nasid = NULL;
+static char *nasipaddress = NULL;
+static char *expect = NULL;
+static char *config_file = NULL;
+static unsigned short port = PW_AUTH_UDP_PORT;
+static int retries = 1;
+static bool verbose = false;
 
 /******************************************************************************