diff --git a/subsys/shell/backends/Kconfig.backends b/subsys/shell/backends/Kconfig.backends
index 2b2e91e2165..545a53dea8d 100644
--- a/subsys/shell/backends/Kconfig.backends
+++ b/subsys/shell/backends/Kconfig.backends
@@ -147,7 +147,7 @@ module = SHELL_BACKEND_RTT
 default-timeout = 100
 source "subsys/shell/Kconfig.template.shell_log_queue_timeout"
 
-default-size = 10
+default-size = 512
 source "subsys/shell/Kconfig.template.shell_log_queue_size"
 
 choice
@@ -243,7 +243,7 @@ module = SHELL_BACKEND_MQTT
 default-timeout = 100
 source "subsys/shell/Kconfig.template.shell_log_queue_timeout"
 
-default-size = 10
+default-size = 512
 source "subsys/shell/Kconfig.template.shell_log_queue_size"
 
 choice
@@ -339,7 +339,7 @@ module = SHELL_TELNET
 default-timeout = 100
 source "subsys/shell/Kconfig.template.shell_log_queue_timeout"
 
-default-size = 10
+default-size = 512
 source "subsys/shell/Kconfig.template.shell_log_queue_size"
 
 choice
diff --git a/subsys/shell/backends/shell_dummy.c b/subsys/shell/backends/shell_dummy.c
index dfc30a6b81e..61cb7725238 100644
--- a/subsys/shell/backends/shell_dummy.c
+++ b/subsys/shell/backends/shell_dummy.c
@@ -10,7 +10,7 @@
 #include <zephyr/init.h>
 
 SHELL_DUMMY_DEFINE(shell_transport_dummy);
-SHELL_DEFINE(shell_dummy, CONFIG_SHELL_PROMPT_DUMMY, &shell_transport_dummy, 1,
+SHELL_DEFINE(shell_dummy, CONFIG_SHELL_PROMPT_DUMMY, &shell_transport_dummy, 256,
 	     0, SHELL_FLAG_OLF_CRLF);
 
 static int init(const struct shell_transport *transport,