diff --git a/library/psa_crypto_core.h b/library/psa_crypto_core.h
index 9863848..37f8162 100644
--- a/library/psa_crypto_core.h
+++ b/library/psa_crypto_core.h
@@ -183,6 +183,14 @@
 }
 #endif
 
+/** Get the description of a key given its identifier and policy constraints
+ *  and lock it.
+ */
+psa_status_t psa_get_and_lock_key_slot_with_policy( mbedtls_svc_key_id_t key,
+                                                    psa_key_slot_t **p_slot,
+                                                    psa_key_usage_t usage,
+                                                    psa_algorithm_t alg );
+
 /** Completely wipe a slot in memory, including its policy.
  *
  * Persistent storage is not affected.
diff --git a/library/psa_crypto_pake.c b/library/psa_crypto_pake.c
index 1deb488..224f922 100644
--- a/library/psa_crypto_pake.c
+++ b/library/psa_crypto_pake.c
@@ -33,11 +33,6 @@
 #include <mbedtls/error.h>
 #include <string.h>
 
-extern psa_status_t psa_get_and_lock_key_slot_with_policy(
-    mbedtls_svc_key_id_t key,
-    psa_key_slot_t **p_slot,
-    psa_key_usage_t usage,
-    psa_algorithm_t alg );
 /*
  * State sequence:
  *