diff --git a/tests/net/lib/mqtt_publisher/prj_tls.conf b/tests/net/lib/mqtt_publisher/prj_tls.conf
index 310c7f4645ee7e..6ca6b98974e8e8 100644
--- a/tests/net/lib/mqtt_publisher/prj_tls.conf
+++ b/tests/net/lib/mqtt_publisher/prj_tls.conf
@@ -42,4 +42,6 @@ CONFIG_MBEDTLS_BUILTIN=y
 CONFIG_MBEDTLS_ENABLE_HEAP=y
 CONFIG_MBEDTLS_HEAP_SIZE=30000
 
+# for tls_entropy_func
+CONFIG_TEST_RANDOM_GENERATOR=y
 CONFIG_ZTEST=y