diff --git a/lib/db/postgres7.php b/lib/db/postgres7.php
index 7c7d52dc5f1..37c5d227c09 100644
--- a/lib/db/postgres7.php
+++ b/lib/db/postgres7.php
@@ -1014,8 +1014,8 @@ function main_upgrade($oldversion=0) {
                               id SERIAL PRIMARY KEY,
                               courseid integer NOT NULL default '0',
                               letter varchar(8) NOT NULL default 'NA',
-                              grade_high decimal(4,2) NOT NULL default '100.00',
-                              grade_low decimal(4,2) NOT NULL default '0.00'
+                              grade_high decimal(6,2) NOT NULL default '100.00',
+                              grade_low decimal(6,2) NOT NULL default '0.00'
                             );");
 
         modify_database('',"CREATE INDEX prefix_grade_letter_courseid_idx ON prefix_grade_letter (courseid);");
diff --git a/lib/db/postgres7.sql b/lib/db/postgres7.sql
index c3ce8d4ce29..266b8c4cde8 100644
--- a/lib/db/postgres7.sql
+++ b/lib/db/postgres7.sql
@@ -177,8 +177,8 @@ CREATE TABLE prefix_grade_letter (
   id SERIAL PRIMARY KEY,
   courseid integer NOT NULL default '0',
   letter varchar(8) NOT NULL default 'NA',
-  grade_high decimal(4,2) NOT NULL default '100.00',
-  grade_low decimal(4,2) NOT NULL default '0.00'
+  grade_high decimal(6,2) NOT NULL default '100.00',
+  grade_low decimal(6,2) NOT NULL default '0.00'
 );
 
 CREATE INDEX prefix_grade_letter_courseid_idx ON prefix_grade_letter (courseid);