diff --git a/ci/ignore_build_warnings.txt b/ci/ignore_build_warnings.txt
index df4e0ba5c5..72e106f135 100644
--- a/ci/ignore_build_warnings.txt
+++ b/ci/ignore_build_warnings.txt
@@ -6,3 +6,4 @@ Warning: Deprecated: Command 'sign_data' is deprecated. Use 'sign-data' instead.
 Warning: Deprecated: Command 'extract_public_key' is deprecated. Use 'extract-public-key' instead.
 warning: unknown kconfig symbol 'EXAMPLE_ETH_PHY_IP101'
 WARNING: The following Kconfig variables were used in "if" clauses, but not
+warning: unknown kconfig symbol 'LIBC_NEWLIB'
diff --git a/components/mosquitto/CMakeLists.txt b/components/mosquitto/CMakeLists.txt
index 5e71918d4d..ee071fd69c 100644
--- a/components/mosquitto/CMakeLists.txt
+++ b/components/mosquitto/CMakeLists.txt
@@ -101,3 +101,5 @@ set(sources_that_define_gnu_source ${m_src_dir}/loop.c ${m_src_dir}/mux_poll.c)
 foreach(offending_src ${sources_that_define_gnu_source})
     set_source_files_properties(${offending_src} PROPERTIES COMPILE_OPTIONS "-U_GNU_SOURCE")
 endforeach()
+
+set_source_files_properties(${m_src_dir}/security_default.c PROPERTIES COMPILE_OPTIONS "-Wno-char-subscripts")
diff --git a/components/mosquitto/examples/broker/sdkconfig.defaults b/components/mosquitto/examples/broker/sdkconfig.defaults
new file mode 100644
index 0000000000..c76fd80b46
--- /dev/null
+++ b/components/mosquitto/examples/broker/sdkconfig.defaults
@@ -0,0 +1 @@
+CONFIG_LIBC_NEWLIB=y
diff --git a/components/mosquitto/examples/serverless_mqtt/sdkconfig.defaults b/components/mosquitto/examples/serverless_mqtt/sdkconfig.defaults
index f0fd9cde6d..d871b0d2a4 100644
--- a/components/mosquitto/examples/serverless_mqtt/sdkconfig.defaults
+++ b/components/mosquitto/examples/serverless_mqtt/sdkconfig.defaults
@@ -4,3 +4,4 @@ CONFIG_PTHREAD_TASK_STACK_SIZE_DEFAULT=32768
 CONFIG_LWIP_SNTP_MAX_SERVERS=2
 CONFIG_MBEDTLS_SSL_PROTO_DTLS=y
 CONFIG_MBEDTLS_SSL_DTLS_SRTP=y
+CONFIG_LIBC_NEWLIB=y
diff --git a/components/mosquitto/port/priv_include/config.h b/components/mosquitto/port/priv_include/config.h
index 545bfaf78e..1cf844802b 100644
--- a/components/mosquitto/port/priv_include/config.h
+++ b/components/mosquitto/port/priv_include/config.h
@@ -16,8 +16,11 @@
 
 #include <ctype.h>
 #include "net/if.h"
+#include "esp_idf_version.h"
 
+#if ESP_IDF_VERSION_MAJOR < 6
 #undef  isspace
 #define isspace(__c) (__ctype_lookup((int)__c)&_S)
+#endif
 
 #define VERSION "v2.0.20~5"