diff --git a/docs/en_US/release_notes_6_3.rst b/docs/en_US/release_notes_6_3.rst
index 5c777702f..75bb8be45 100644
--- a/docs/en_US/release_notes_6_3.rst
+++ b/docs/en_US/release_notes_6_3.rst
@@ -18,3 +18,4 @@ Bug fixes
 *********
 
 | `Issue #6906 <https://redmine.postgresql.org/issues/6906>`_ -  Fixed an issue where referenced table drop-down should be disabled in foreign key -> columns after one row is added.
+| `Issue #6986 <https://redmine.postgresql.org/issues/6986>`_ -  Fixed an issue where the user can't debug function with timestamp parameter.
diff --git a/web/pgadmin/tools/debugger/templates/debugger/sql/execute_plpgsql.sql b/web/pgadmin/tools/debugger/templates/debugger/sql/execute_plpgsql.sql
index 2295f9446..6e90ef83d 100644
--- a/web/pgadmin/tools/debugger/templates/debugger/sql/execute_plpgsql.sql
+++ b/web/pgadmin/tools/debugger/templates/debugger/sql/execute_plpgsql.sql
@@ -11,9 +11,9 @@
 {% if data %}
 {% for dict_item in data %}
 {% if 'type' in dict_item and 'value' in dict_item %}
-{% if dict_item['value'] != 'NULL' and '[]' not in dict_item['type'] %}
+{% if ('NULL:' not in dict_item['value']|string and dict_item['value'] != 'NULL' and '[]' not in dict_item['type']) %}
 {{ dict_item['value']|qtLiteral }}::{{ dict_item['type'] }}{% if not loop.last %}, {% endif %}
-{% elif dict_item['value'] == 'NULL' %}
+{% elif dict_item['value'] == 'NULL' or 'NULL:' in dict_item['value'] %}
 {{ dict_item['value'] }}::{{ dict_item['type'] }}{% if not loop.last %}, {% endif %}
 {% else %}
 {% if '[]' in dict_item['type'] %}