diff --git a/jOOQ/src/main/java/org/jooq/impl/DateDiff.java b/jOOQ/src/main/java/org/jooq/impl/DateDiff.java
index d076bf4b1e..8ef93a03a1 100644
--- a/jOOQ/src/main/java/org/jooq/impl/DateDiff.java
+++ b/jOOQ/src/main/java/org/jooq/impl/DateDiff.java
@@ -96,6 +96,9 @@ class DateDiff extends AbstractFunction<Integer> {
             xx [/pro] */
             case CUBRID:
             case POSTGRES:
+
+                // [#4481] Parentheses are important in case this expression is
+                //         placed in the context of other arithmetic
                 return field("({0} - {1})", getDataType(), date1, date2);
 
             /* [pro] xx
diff --git a/jOOQ/src/main/java/org/jooq/impl/TimestampDiff.java b/jOOQ/src/main/java/org/jooq/impl/TimestampDiff.java
index 0ebe00f372..c5ab4cf5ae 100644
--- a/jOOQ/src/main/java/org/jooq/impl/TimestampDiff.java
+++ b/jOOQ/src/main/java/org/jooq/impl/TimestampDiff.java
@@ -106,6 +106,9 @@ class TimestampDiff extends AbstractFunction<DayToSecond> {
             xxxx xxxxxxx
             xx [/pro] */
             case POSTGRES:
+
+                // [#4481] Parentheses are important in case this expression is
+                //         placed in the context of other arithmetic
                 return field("({0} - {1})", getDataType(), timestamp1, timestamp2);
 
             // CUBRID's datetime operations operate on a millisecond level