diff --git a/configs/config-ccm-psk-tls1_2.h b/configs/config-ccm-psk-tls1_2.h
index c58d150..db730f2 100644
--- a/configs/config-ccm-psk-tls1_2.h
+++ b/configs/config-ccm-psk-tls1_2.h
@@ -49,6 +49,7 @@
 #define MBEDTLS_MD_C
 #define MBEDTLS_NET_C
 #define MBEDTLS_SHA256_C
+#define MBEDTLS_SHA224_C
 #define MBEDTLS_SSL_CLI_C
 #define MBEDTLS_SSL_SRV_C
 #define MBEDTLS_SSL_TLS_C