diff --git a/src/bin/psql/t/010_tab_completion.pl b/src/bin/psql/t/010_tab_completion.pl
index 1d2e5f5b92a..64e27ef87a3 100644
--- a/src/bin/psql/t/010_tab_completion.pl
+++ b/src/bin/psql/t/010_tab_completion.pl
@@ -44,7 +44,9 @@ $node->safe_psql('postgres',
 	  . "CREATE TABLE mytab246 (f1 int, f2 text);\n"
 	  . "CREATE TABLE \"mixedName\" (f1 int, f2 text);\n"
 	  . "CREATE TYPE enum1 AS ENUM ('foo', 'bar', 'baz', 'BLACK');\n"
-	  . "CREATE PUBLICATION some_publication;\n");
+	  . "CREATE PUBLICATION some_publication;\n"
+	  . "CREATE TABLE fpo_test (id int4range, valid_at daterange, name text);\n"
+);
 
 # In a VPATH build, we'll be started in the source directory, but we want
 # to run in the build directory so that we can use relative paths to
@@ -422,6 +424,42 @@ check_completion(
 
 clear_line();
 
+# check tab completion for DELETE ... FOR PORTION OF
+check_completion(
+	"DELETE FROM fpo_test F\t",
+	qr/FOR /,
+	"complete DELETE FROM <table> F<tab> to FOR");
+
+check_completion("P\t", qr/PORTION /, "complete FOR P<tab> to PORTION");
+
+check_completion("O\t", qr/OF /, "complete PORTION O<tab> to OF");
+
+check_completion("v\t", qr/valid_at /,
+	"complete FOR PORTION OF offers column names");
+
+check_completion("FR\t", qr/FROM /,
+	"complete FOR PORTION OF <col> FR<tab> to FROM");
+
+clear_query();
+
+# check tab completion for UPDATE ... FOR PORTION OF
+check_completion(
+	"UPDATE fpo_test F\t",
+	qr/FOR /,
+	"complete UPDATE <table> F<tab> to FOR");
+
+check_completion("P\t", qr/PORTION /, "complete FOR P<tab> to PORTION");
+
+check_completion("O\t", qr/OF /, "complete PORTION O<tab> to OF");
+
+check_completion("v\t", qr/valid_at /,
+	"complete FOR PORTION OF offers column names");
+
+check_completion("FR\t", qr/FROM /,
+	"complete FOR PORTION OF <col> FR<tab> to FROM");
+
+clear_query();
+
 # send psql an explicit \q to shut it down, else pty won't close properly
 $h->quit or die "psql returned $?";
 
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index db65d130fcb..1335479d2aa 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -4362,7 +4362,19 @@ match_previous_words(int pattern_id,
 		COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_updatables);
 	/* Complete DELETE FROM <table> */
 	else if (TailMatches("DELETE", "FROM", MatchAny))
-		COMPLETE_WITH("USING", "WHERE");
+		COMPLETE_WITH("FOR", "USING", "WHERE");
+	/* Complete DELETE FROM <table> FOR with PORTION */
+	else if (TailMatches("DELETE", "FROM", MatchAny, "FOR"))
+		COMPLETE_WITH("PORTION");
+	/* Complete DELETE FROM <table> FOR PORTION with OF */
+	else if (TailMatches("DELETE", "FROM", MatchAny, "FOR", "PORTION"))
+		COMPLETE_WITH("OF");
+	/* Complete DELETE FROM <table> FOR PORTION OF with column names */
+	else if (TailMatches("DELETE", "FROM", MatchAny, "FOR", "PORTION", "OF"))
+		COMPLETE_WITH_ATTR(prev4_wd);
+	/* Complete DELETE FROM <table> FOR PORTION OF <period> with FROM */
+	else if (TailMatches("DELETE", "FROM", MatchAny, "FOR", "PORTION", "OF", MatchAny))
+		COMPLETE_WITH("FROM");
 	/* Complete DELETE FROM <table> USING with relations supporting SELECT */
 	else if (TailMatches("DELETE", "FROM", MatchAny, "USING"))
 		COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_selectables);
@@ -5434,9 +5446,21 @@ match_previous_words(int pattern_id,
 	/* If prev. word is UPDATE suggest a list of tables */
 	else if (TailMatches("UPDATE"))
 		COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_updatables);
-	/* Complete UPDATE <table> with "SET" */
+	/* Complete UPDATE <table> with "SET" or "FOR" (for FOR PORTION OF) */
 	else if (TailMatches("UPDATE", MatchAny))
-		COMPLETE_WITH("SET");
+		COMPLETE_WITH("FOR", "SET");
+	/* Complete UPDATE <table> FOR with PORTION */
+	else if (TailMatches("UPDATE", MatchAny, "FOR"))
+		COMPLETE_WITH("PORTION");
+	/* Complete UPDATE <table> FOR PORTION with OF */
+	else if (TailMatches("UPDATE", MatchAny, "FOR", "PORTION"))
+		COMPLETE_WITH("OF");
+	/* Complete UPDATE <table> FOR PORTION OF with column names */
+	else if (TailMatches("UPDATE", MatchAny, "FOR", "PORTION", "OF"))
+		COMPLETE_WITH_ATTR(prev4_wd);
+	/* Complete UPDATE <table> FOR PORTION OF <period> with FROM */
+	else if (TailMatches("UPDATE", MatchAny, "FOR", "PORTION", "OF", MatchAny))
+		COMPLETE_WITH("FROM");
 	/* Complete UPDATE <table> SET with list of attributes */
 	else if (TailMatches("UPDATE", MatchAny, "SET"))
 		COMPLETE_WITH_ATTR(prev2_wd);