diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index d53a09da3b..a0e58a2712 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -1891,6 +1891,10 @@ static void psa_fail_key_creation(psa_key_slot_t *slot,
         return;
     }
 
+#if defined(MBEDTLS_THREADING_C)
+    mbedtls_mutex_lock(&mbedtls_threading_key_slot_mutex);
+#endif
+
 #if defined(MBEDTLS_PSA_CRYPTO_SE_C)
     /* TODO: If the key has already been created in the secure
      * element, and the failure happened later (when saving metadata
@@ -1909,6 +1913,10 @@ static void psa_fail_key_creation(psa_key_slot_t *slot,
 #endif /* MBEDTLS_PSA_CRYPTO_SE_C */
 
     psa_wipe_key_slot(slot);
+
+#if defined(MBEDTLS_THREADING_C)
+    mbedtls_mutex_unlock(&mbedtls_threading_key_slot_mutex);
+#endif
 }
 
 /** Validate optional attributes during key creation.