diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 8c58ff5..f3a2258 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -4315,6 +4315,13 @@
             mbedtls_free( operation->ctx.tls12_prf.label );
         }
 
+        if( operation->ctx.tls12_prf.other_secret != NULL )
+        {
+            mbedtls_platform_zeroize( operation->ctx.tls12_prf.other_secret,
+                                      operation->ctx.tls12_prf.other_secret_length );
+            mbedtls_free( operation->ctx.tls12_prf.other_secret );
+        }
+
         status = PSA_SUCCESS;
 
         /* We leave the fields Ai and output_block to be erased safely by the