diff --git a/src/dsql/ddl.cpp b/src/dsql/ddl.cpp
index 06c9e64f55..21dd83ce31 100644
--- a/src/dsql/ddl.cpp
+++ b/src/dsql/ddl.cpp
@@ -2650,11 +2650,39 @@ static void define_procedure( dsql_req* request, NOD_TYPE op)
 	request->append_uchar(blr_short);
 	request->append_uchar(0);
 
-	if (inputs) {
+	if (inputs)
+	{
 		request->append_uchar(blr_receive);
 		request->append_uchar(0);
 	}
+
 	request->append_uchar(blr_begin);
+
+	if (inputs)
+	{
+		parameters = procedure_node->nod_arg[e_prc_inputs];
+		dsql_nod** ptr = parameters->nod_arg;
+		for (const dsql_nod* const* const end = ptr + parameters->nod_count;
+			 ptr < end; ptr++)
+		{
+			dsql_nod* parameter = *ptr;
+			dsql_var* variable = (dsql_var*) parameter->nod_arg[e_var_variable];
+			dsql_fld* field = variable->var_field;
+
+			if (field->fld_constrained || field->fld_not_nullable)
+			{
+				// ASF: To validate input parameters we need only to read his value.
+				// Assigning it to null is an easy way to do this.
+				request->append_uchar(blr_assignment);
+				request->append_uchar(blr_parameter2);
+				request->append_uchar(variable->var_msg_number);
+				request->append_ushort(variable->var_msg_item);
+				request->append_ushort(variable->var_msg_item + 1);
+				request->append_uchar(blr_null);
+			}
+		}
+	}
+
 	if (outputs)
 	{
 		parameters = procedure_node->nod_arg[e_prc_outputs];