diff --git a/library/x509_crt.c b/library/x509_crt.c
index 65b464a..9b3414a 100644
--- a/library/x509_crt.c
+++ b/library/x509_crt.c
@@ -47,6 +47,7 @@
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
 #include "psa/crypto.h"
 #include "mbedtls/psa_util.h"
+#include "md_psa.h"
 #endif /* MBEDTLS_USE_PSA_CRYPTO */
 #include "x509_invasive.h"
 #include "pk_internal.h"