diff --git a/interface/src/psa/psa_client.c b/interface/src/psa/psa_client.c
index 00d95ee..6960ac6 100644
--- a/interface/src/psa/psa_client.c
+++ b/interface/src/psa/psa_client.c
@@ -56,10 +56,9 @@
 {
     if ((type > INT16_MAX) ||
         (type < INT16_MIN) ||
-        (in_len > PSA_MAX_IOVEC) ||
-        (out_len > PSA_MAX_IOVEC) ||
-        ((in_len + out_len) > PSA_MAX_IOVEC)) {
-        return PSA_ERROR_INVALID_ARGUMENT;
+        (in_len > UINT8_MAX) ||
+        (out_len > UINT8_MAX)) {
+        return PSA_ERROR_PROGRAMMER_ERROR;
     }
 
     return psa_call_param_pack(handle,
diff --git a/interface/src/tfm_psa_ns_api.c b/interface/src/tfm_psa_ns_api.c
index 9d60a11..751216d 100644
--- a/interface/src/tfm_psa_ns_api.c
+++ b/interface/src/tfm_psa_ns_api.c
@@ -50,10 +50,9 @@
 {
     if ((type > INT16_MAX) ||
         (type < INT16_MIN) ||
-        (in_len > PSA_MAX_IOVEC) ||
-        (out_len > PSA_MAX_IOVEC) ||
-        ((in_len + out_len) > PSA_MAX_IOVEC)) {
-        return PSA_ERROR_INVALID_ARGUMENT;
+        (in_len > UINT8_MAX) ||
+        (out_len > UINT8_MAX)) {
+        return PSA_ERROR_PROGRAMMER_ERROR;
     }
 
     return tfm_ns_interface_dispatch(