diff --git a/source/portable/mbedtls/core_pkcs11_mbedtls.c b/source/portable/mbedtls/core_pkcs11_mbedtls.c
index b14c2902..a774e053 100644
--- a/source/portable/mbedtls/core_pkcs11_mbedtls.c
+++ b/source/portable/mbedtls/core_pkcs11_mbedtls.c
@@ -476,7 +476,7 @@ static CK_RV prvMbedTLS_Initialize( void )
     mbedtls_ctr_drbg_init( &xP11Context.xMbedDrbgCtx );
 
     /* Initialise the global mutexes for the PSA API's */
-    #if defined( MBEDTLS_PSA_CRYPTO_C )
+    #if defined( MBEDTLS_PSA_CRYPTO_C ) && ( MBEDTLS_VERSION_NUMBER >= 0x03060300 )
         mbedtls_mutex_init( &mbedtls_threading_key_slot_mutex );
         mbedtls_mutex_init( &mbedtls_threading_psa_globaldata_mutex );
         mbedtls_mutex_init( &mbedtls_threading_psa_rngdata_mutex );