diff --git a/tests/periph_uart/main.c b/tests/periph_uart/main.c
index e0f9cf88f9..90afb22167 100644
--- a/tests/periph_uart/main.c
+++ b/tests/periph_uart/main.c
@@ -28,9 +28,12 @@
 #include "msg.h"
 #include "ringbuffer.h"
 #include "periph/uart.h"
-#include "stdio_uart.h"
 #include "xtimer.h"
 
+#ifdef MODULE_STDIO_UART
+#include "stdio_uart.h"
+#endif
+
 #ifndef SHELL_BUFSIZE
 #define SHELL_BUFSIZE       (128U)
 #endif
@@ -283,11 +286,15 @@ int main(void)
      * value given in STDIO_UART_DEV is not a numeral (depends on the CPU
      * implementation), so we rather break the output by printing a
      * non-numerical value instead of breaking the UART device descriptor */
-    sleep_test(STDIO_UART_DEV, STDIO_UART_DEV);
+    if (STDIO_UART_DEV != UART_UNDEF) {
+        sleep_test(STDIO_UART_DEV, STDIO_UART_DEV);
+    }
 
     puts("\nUART INFO:");
     printf("Available devices:               %i\n", UART_NUMOF);
-    printf("UART used for STDIO (the shell): UART_DEV(%i)\n\n", STDIO_UART_DEV);
+    if (STDIO_UART_DEV != UART_UNDEF) {
+        printf("UART used for STDIO (the shell): UART_DEV(%i)\n\n", STDIO_UART_DEV);
+    }
 
     /* initialize ringbuffers */
     for (unsigned i = 0; i < UART_NUMOF; i++) {