diff --git a/tests/scripts/components-configuration-tls.sh b/tests/scripts/components-configuration-tls.sh
index 5511cc9..7debb34 100644
--- a/tests/scripts/components-configuration-tls.sh
+++ b/tests/scripts/components-configuration-tls.sh
@@ -315,14 +315,14 @@
     msg "build: full config except SSL server, make, gcc" # ~ 30s
     scripts/config.py full
     scripts/config.py unset MBEDTLS_SSL_SRV_C
-    make CC=gcc CFLAGS='-Werror -Wall -Wextra -O1'
+    make CC=gcc CFLAGS='-Werror -Wall -Wextra -O1 -Wmissing-prototypes'
 }
 
 component_build_no_ssl_cli () {
     msg "build: full config except SSL client, make, gcc" # ~ 30s
     scripts/config.py full
     scripts/config.py unset MBEDTLS_SSL_CLI_C
-    make CC=gcc CFLAGS='-Werror -Wall -Wextra -O1'
+    make CC=gcc CFLAGS='-Werror -Wall -Wextra -O1 -Wmissing-prototypes'
 }
 
 component_test_no_max_fragment_length () {