diff --git a/samples/net/civetweb/http_server/prj.conf b/samples/net/civetweb/http_server/prj.conf
index 0ae5434230b..3b80108a67b 100644
--- a/samples/net/civetweb/http_server/prj.conf
+++ b/samples/net/civetweb/http_server/prj.conf
@@ -30,3 +30,7 @@ CONFIG_NET_CONFIG_PEER_IPV4_ADDR="192.0.2.2"
 
 # logging
 CONFIG_NET_LOG=y
+
+# Do not include mbedtls via this option as civetweb does not
+# work properly with mbedtls.
+CONFIG_NET_TCP_ISN_RFC6528=n
diff --git a/samples/net/civetweb/websocket_server/prj.conf b/samples/net/civetweb/websocket_server/prj.conf
index 6b2ec8bd257..b582bdd9219 100644
--- a/samples/net/civetweb/websocket_server/prj.conf
+++ b/samples/net/civetweb/websocket_server/prj.conf
@@ -34,3 +34,7 @@ CONFIG_IDLE_STACK_SIZE=1024
 CONFIG_LOG=y
 # CONFIG_NET_LOG=y
 # CONFIG_LOG_STRDUP_MAX_STRING=256
+
+# Do not include mbedtls via this option as civetweb does not
+# work properly with mbedtls.
+CONFIG_NET_TCP_ISN_RFC6528=n