diff --git a/library/pkwrite.c b/library/pkwrite.c
index 439428c..eee64ab 100644
--- a/library/pkwrite.c
+++ b/library/pkwrite.c
@@ -77,7 +77,7 @@
     return 0;
 }
 
-#if defined(MBEDTLS_USE_PSA_CRYPTO)
+#if defined(MBEDTLS_USE_PSA_CRYPTO) && defined(MBEDTLS_PEM_WRITE_C)
 /* It is assumed that the input key is opaque */
 static psa_ecc_family_t pk_get_opaque_ec_family(const mbedtls_pk_context *pk)
 {
@@ -92,7 +92,7 @@
 
     return ec_family;
 }
-#endif /* MBETLS_USE_PSA_CRYPTO */
+#endif /* MBETLS_USE_PSA_CRYPTO && MBEDTLS_PEM_WRITE_C */
 #endif /* MBEDTLS_PK_HAVE_RFC8410_CURVES */
 #endif /* MBEDTLS_PK_HAVE_ECC_KEYS */