diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 186b64f..4fe20b4 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -133,7 +133,9 @@
     (void) hash_alg;
     return global_data.drivers_initialized;
 }
-
+#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DH_KEY_PAIR) ||       \
+    defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DH_PUBLIC_KEY) ||     \
+    defined(PSA_WANT_KEY_TYPE_DH_KEY_PAIR)
 static int psa_is_dh_key_size_valid(size_t bits) {
     if (bits != 2048 && bits != 3072 && bits != 4096 &&
         bits != 6144 && bits != 8192) {
@@ -142,6 +144,9 @@
 
     return 1;
 }
+#endif /* MBEDTLS_PSA_BUILTIN_KEY_TYPE_DH_KEY_PAIR ||
+          MBEDTLS_PSA_BUILTIN_KEY_TYPE_DH_PUBLIC_KEY ||
+          PSA_WANT_KEY_TYPE_DH_KEY_PAIR */
 
 psa_status_t mbedtls_to_psa_error(int ret)
 {