diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index d3ac4ce..419be16 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -3286,7 +3286,7 @@
 exit:
 
     /* Update ops count with work done. */
-    operation->num_ops += psa_driver_wrapper_sign_hash_get_num_ops(operation);
+    operation->num_ops = psa_driver_wrapper_sign_hash_get_num_ops(operation);
 
     if (status != PSA_OPERATION_INCOMPLETE) {
         psa_wipe_output_buffer(signature, status, signature_size,
@@ -3413,7 +3413,7 @@
 exit:
 
     /* Update ops count with work done. */
-    operation->num_ops += psa_driver_wrapper_verify_hash_get_num_ops(
+    operation->num_ops = psa_driver_wrapper_verify_hash_get_num_ops(
         operation);
 
     if (status != PSA_OPERATION_INCOMPLETE) {