diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index afb4d32..2712c67 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -43,6 +43,7 @@
 
 #include "psa/crypto.h"
 
+#include "psa_crypto_core.h"
 #include "psa_crypto_invasive.h"
 #include "psa_crypto_slot_management.h"
 /* Include internal declarations that are useful for implementing persistently
@@ -113,29 +114,6 @@
 /* Global data, support functions and library management */
 /****************************************************************/
 
-typedef struct
-{
-    psa_key_type_t type;
-    psa_key_policy_t policy;
-    psa_key_lifetime_t lifetime;
-    psa_key_id_t persistent_storage_id;
-    unsigned allocated : 1;
-    union
-    {
-        struct raw_data
-        {
-            uint8_t *data;
-            size_t bytes;
-        } raw;
-#if defined(MBEDTLS_RSA_C)
-        mbedtls_rsa_context *rsa;
-#endif /* MBEDTLS_RSA_C */
-#if defined(MBEDTLS_ECP_C)
-        mbedtls_ecp_keypair *ecp;
-#endif /* MBEDTLS_ECP_C */
-    } data;
-} psa_key_slot_t;
-
 static int key_type_is_raw_bytes( psa_key_type_t type )
 {
     return( PSA_KEY_TYPE_IS_UNSTRUCTURED( type ) );
diff --git a/library/psa_crypto_core.h b/library/psa_crypto_core.h
new file mode 100644
index 0000000..de877d3
--- /dev/null
+++ b/library/psa_crypto_core.h
@@ -0,0 +1,62 @@
+/*
+ *  PSA crypto core internal interfaces
+ */
+/*  Copyright (C) 2018, ARM Limited, All Rights Reserved
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *  This file is part of mbed TLS (https://tls.mbed.org)
+ */
+
+#ifndef PSA_CRYPTO_CORE_H
+#define PSA_CRYPTO_CORE_H
+
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "mbedtls/config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
+#include "psa/crypto.h"
+
+#include "mbedtls/ecp.h"
+#include "mbedtls/rsa.h"
+
+/** The data structure representing a key slot, containing key material
+ * and metadata for one key.
+ */
+typedef struct
+{
+    psa_key_type_t type;
+    psa_key_policy_t policy;
+    psa_key_lifetime_t lifetime;
+    psa_key_id_t persistent_storage_id;
+    unsigned allocated : 1;
+    union
+    {
+        struct raw_data
+        {
+            uint8_t *data;
+            size_t bytes;
+        } raw;
+#if defined(MBEDTLS_RSA_C)
+        mbedtls_rsa_context *rsa;
+#endif /* MBEDTLS_RSA_C */
+#if defined(MBEDTLS_ECP_C)
+        mbedtls_ecp_keypair *ecp;
+#endif /* MBEDTLS_ECP_C */
+    } data;
+} psa_key_slot_t;
+
+#endif /* PSA_CRYPTO_CORE_H */
diff --git a/visualc/VS2010/mbedTLS.vcxproj b/visualc/VS2010/mbedTLS.vcxproj
index 341e058..366b97e 100644
--- a/visualc/VS2010/mbedTLS.vcxproj
+++ b/visualc/VS2010/mbedTLS.vcxproj
@@ -231,6 +231,7 @@
     <ClInclude Include="..\..\include\psa\crypto_platform.h" />
     <ClInclude Include="..\..\include\psa\crypto_sizes.h" />
     <ClInclude Include="..\..\include\psa\crypto_struct.h" />
+    <ClInclude Include="..\..\library/psa_crypto_core.h" />
     <ClInclude Include="..\..\library/psa_crypto_invasive.h" />
     <ClInclude Include="..\..\library/psa_crypto_slot_management.h" />
     <ClInclude Include="..\..\library/psa_crypto_storage.h" />