diff --git a/tests/sys/shell/Makefile.ci b/tests/sys/shell/Makefile.ci
index 6dd70e79649f2..d17460b54170b 100644
--- a/tests/sys/shell/Makefile.ci
+++ b/tests/sys/shell/Makefile.ci
@@ -1,4 +1,7 @@
 BOARD_INSUFFICIENT_MEMORY := \
+    arduino-duemilanove \
+    arduino-uno \
+    atmega328p \
     atmega328p-xplained-mini \
     atmega8 \
     #
diff --git a/tests/sys/shell/main.c b/tests/sys/shell/main.c
index 46fec268c9d93..146ab4d7ae0d0 100644
--- a/tests/sys/shell/main.c
+++ b/tests/sys/shell/main.c
@@ -101,7 +101,7 @@ static int print_empty(int argc, char **argv)
     return 0;
 }
 
-static char _stack[THREAD_STACKSIZE_TINY];
+static char _stack[THREAD_STACKSIZE_SMALL];
 static struct {
     uint16_t period_ms;
     uint16_t reps;