diff --git a/tests/drivers/at/main.c b/tests/drivers/at/main.c
index 35feb2359a4f..46a7f22eeaac 100644
--- a/tests/drivers/at/main.c
+++ b/tests/drivers/at/main.c
@@ -35,8 +35,8 @@ static at_dev_t at_dev;
 static char buf[256];
 static char resp[1024];
 static char rp_buf[256];
-static bool initialized;
-static bool is_power_on;
+static bool initialized = false;
+static bool is_power_on = false;
 
 static int init(int argc, char **argv)
 {
@@ -490,9 +490,6 @@ int main(void)
 {
     puts("AT command test app");
 
-    initialized = false;
-    is_power_on = false;
-
     /* run the shell */
     char line_buf[SHELL_DEFAULT_BUFSIZE];
     shell_run(shell_commands, line_buf, SHELL_DEFAULT_BUFSIZE);