diff --git a/include/mbedtls/threading.h b/include/mbedtls/threading.h
index fbd7ad2e47..d50d04ead1 100644
--- a/include/mbedtls/threading.h
+++ b/include/mbedtls/threading.h
@@ -114,11 +114,18 @@ extern mbedtls_threading_mutex_t mbedtls_threading_gmtime_mutex;
 extern mbedtls_threading_mutex_t mbedtls_threading_key_slot_mutex;
 
 /*
- * A mutex used to make the PSA global_data struct members thread safe.
+ * A mutex used to make the non-rng PSA global_data struct members thread safe.
  *
- * This mutex must be held when any read or write to a any of the PSA
- * global_data structure members. */
+ * This mutex must be held when reading or writing to any of the PSA global_data
+ * structure members, other than the rng_state or rng struct. */
 extern mbedtls_threading_mutex_t mbedtls_threading_psa_globaldata_mutex;
+
+/*
+ * A mutex used to make the PSA global_data rng data thread safe.
+ *
+ * This mutex must be held when reading or writing to the PSA
+ * global_data rng_state or rng struct members. */
+extern mbedtls_threading_mutex_t mbedtls_threading_psa_rngdata_mutex;
 #endif
 
 #endif /* MBEDTLS_THREADING_C */
diff --git a/library/threading.c b/library/threading.c
index 06b474726c..85db243f21 100644
--- a/library/threading.c
+++ b/library/threading.c
@@ -151,6 +151,7 @@ void mbedtls_threading_set_alt(void (*mutex_init)(mbedtls_threading_mutex_t *),
 #if defined(MBEDTLS_PSA_CRYPTO_C)
     mbedtls_mutex_init(&mbedtls_threading_key_slot_mutex);
     mbedtls_mutex_init(&mbedtls_threading_psa_globaldata_mutex);
+    mbedtls_mutex_init(&mbedtls_threading_psa_rngdata_mutex);
 #endif
 }
 
@@ -168,6 +169,7 @@ void mbedtls_threading_free_alt(void)
 #if defined(MBEDTLS_PSA_CRYPTO_C)
     mbedtls_mutex_free(&mbedtls_threading_key_slot_mutex);
     mbedtls_mutex_free(&mbedtls_threading_psa_globaldata_mutex);
+    mbedtls_mutex_free(&mbedtls_threading_psa_rngdata_mutex);
 #endif
 }
 #endif /* MBEDTLS_THREADING_ALT */
@@ -187,6 +189,7 @@ mbedtls_threading_mutex_t mbedtls_threading_gmtime_mutex MUTEX_INIT;
 #if defined(MBEDTLS_PSA_CRYPTO_C)
 mbedtls_threading_mutex_t mbedtls_threading_key_slot_mutex MUTEX_INIT;
 mbedtls_threading_mutex_t mbedtls_threading_psa_globaldata_mutex MUTEX_INIT;
+mbedtls_threading_mutex_t mbedtls_threading_psa_rngdata_mutex MUTEX_INIT;
 #endif
 
 #endif /* MBEDTLS_THREADING_C */