diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index 2c74de9921b..9918c226c28 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -5924,6 +5924,7 @@ DoesMultiXactIdConflict(MultiXactId multi, uint16 infomask,
 	int		nmembers;
 	MultiXactMember *members;
 	bool	result = false;
+	LOCKMODE wanted = tupleLockExtraInfo[lockmode].hwlock;
 
 	allow_old = !(infomask & HEAP_LOCK_MASK) && HEAP_XMAX_IS_LOCKED_ONLY(infomask);
 	nmembers = GetMultiXactIdMembers(multi, &members, allow_old);
@@ -5934,11 +5935,12 @@ DoesMultiXactIdConflict(MultiXactId multi, uint16 infomask,
 		for (i = 0; i < nmembers; i++)
 		{
 			TransactionId		memxid;
-			LockTupleMode		memlockmode;
+			LOCKMODE			memlockmode;
 
 			memlockmode = LOCKMODE_from_mxstatus(members[i].status);
+
 			/* ignore members that don't conflict with the lock we want */
-			if (!DoLockModesConflict(memlockmode, lockmode))
+			if (!DoLockModesConflict(memlockmode, wanted))
 				continue;
 
 			/* ignore members from current xact */
diff --git a/src/test/isolation/expected/tuplelock-conflict.out b/src/test/isolation/expected/tuplelock-conflict.out
new file mode 100644
index 00000000000..1f5c142aee2
--- /dev/null
+++ b/src/test/isolation/expected/tuplelock-conflict.out
@@ -0,0 +1,469 @@
+Parsed test spec with 2 sessions
+
+starting permutation: s1_begin s1_lcksvpt s1_tuplock1 s2_tuplock1 s1_commit
+step s1_begin: BEGIN;
+step s1_lcksvpt: SELECT * FROM multixact_conflict FOR KEY SHARE; SAVEPOINT foo;
+a              
+
+1              
+step s1_tuplock1: SELECT * FROM multixact_conflict FOR KEY SHARE;
+a              
+
+1              
+step s2_tuplock1: SELECT * FROM multixact_conflict FOR KEY SHARE;
+a              
+
+1              
+step s1_commit: COMMIT;
+
+starting permutation: s1_begin s1_lcksvpt s1_tuplock1 s2_tuplock2 s1_commit
+step s1_begin: BEGIN;
+step s1_lcksvpt: SELECT * FROM multixact_conflict FOR KEY SHARE; SAVEPOINT foo;
+a              
+
+1              
+step s1_tuplock1: SELECT * FROM multixact_conflict FOR KEY SHARE;
+a              
+
+1              
+step s2_tuplock2: SELECT * FROM multixact_conflict FOR SHARE;
+a              
+
+1              
+step s1_commit: COMMIT;
+
+starting permutation: s1_begin s1_lcksvpt s1_tuplock1 s2_tuplock3 s1_commit
+step s1_begin: BEGIN;
+step s1_lcksvpt: SELECT * FROM multixact_conflict FOR KEY SHARE; SAVEPOINT foo;
+a              
+
+1              
+step s1_tuplock1: SELECT * FROM multixact_conflict FOR KEY SHARE;
+a              
+
+1              
+step s2_tuplock3: SELECT * FROM multixact_conflict FOR NO KEY UPDATE;
+a              
+
+1              
+step s1_commit: COMMIT;
+
+starting permutation: s1_begin s1_lcksvpt s1_tuplock1 s2_tuplock4 s1_commit
+step s1_begin: BEGIN;
+step s1_lcksvpt: SELECT * FROM multixact_conflict FOR KEY SHARE; SAVEPOINT foo;
+a              
+
+1              
+step s1_tuplock1: SELECT * FROM multixact_conflict FOR KEY SHARE;
+a              
+
+1              
+step s2_tuplock4: SELECT * FROM multixact_conflict FOR UPDATE; <waiting ...>
+step s1_commit: COMMIT;
+step s2_tuplock4: <... completed>
+a              
+
+1              
+
+starting permutation: s1_begin s1_lcksvpt s1_tuplock2 s2_tuplock1 s1_commit
+step s1_begin: BEGIN;
+step s1_lcksvpt: SELECT * FROM multixact_conflict FOR KEY SHARE; SAVEPOINT foo;
+a              
+
+1              
+step s1_tuplock2: SELECT * FROM multixact_conflict FOR SHARE;
+a              
+
+1              
+step s2_tuplock1: SELECT * FROM multixact_conflict FOR KEY SHARE;
+a              
+
+1              
+step s1_commit: COMMIT;
+
+starting permutation: s1_begin s1_lcksvpt s1_tuplock2 s2_tuplock2 s1_commit
+step s1_begin: BEGIN;
+step s1_lcksvpt: SELECT * FROM multixact_conflict FOR KEY SHARE; SAVEPOINT foo;
+a              
+
+1              
+step s1_tuplock2: SELECT * FROM multixact_conflict FOR SHARE;
+a              
+
+1              
+step s2_tuplock2: SELECT * FROM multixact_conflict FOR SHARE;
+a              
+
+1              
+step s1_commit: COMMIT;
+
+starting permutation: s1_begin s1_lcksvpt s1_tuplock2 s2_tuplock3 s1_commit
+step s1_begin: BEGIN;
+step s1_lcksvpt: SELECT * FROM multixact_conflict FOR KEY SHARE; SAVEPOINT foo;
+a              
+
+1              
+step s1_tuplock2: SELECT * FROM multixact_conflict FOR SHARE;
+a              
+
+1              
+step s2_tuplock3: SELECT * FROM multixact_conflict FOR NO KEY UPDATE; <waiting ...>
+step s1_commit: COMMIT;
+step s2_tuplock3: <... completed>
+a              
+
+1              
+
+starting permutation: s1_begin s1_lcksvpt s1_tuplock2 s2_tuplock4 s1_commit
+step s1_begin: BEGIN;
+step s1_lcksvpt: SELECT * FROM multixact_conflict FOR KEY SHARE; SAVEPOINT foo;
+a              
+
+1              
+step s1_tuplock2: SELECT * FROM multixact_conflict FOR SHARE;
+a              
+
+1              
+step s2_tuplock4: SELECT * FROM multixact_conflict FOR UPDATE; <waiting ...>
+step s1_commit: COMMIT;
+step s2_tuplock4: <... completed>
+a              
+
+1              
+
+starting permutation: s1_begin s1_lcksvpt s1_tuplock3 s2_tuplock1 s1_commit
+step s1_begin: BEGIN;
+step s1_lcksvpt: SELECT * FROM multixact_conflict FOR KEY SHARE; SAVEPOINT foo;
+a              
+
+1              
+step s1_tuplock3: SELECT * FROM multixact_conflict FOR NO KEY UPDATE;
+a              
+
+1              
+step s2_tuplock1: SELECT * FROM multixact_conflict FOR KEY SHARE;
+a              
+
+1              
+step s1_commit: COMMIT;
+
+starting permutation: s1_begin s1_lcksvpt s1_tuplock3 s2_tuplock2 s1_commit
+step s1_begin: BEGIN;
+step s1_lcksvpt: SELECT * FROM multixact_conflict FOR KEY SHARE; SAVEPOINT foo;
+a              
+
+1              
+step s1_tuplock3: SELECT * FROM multixact_conflict FOR NO KEY UPDATE;
+a              
+
+1              
+step s2_tuplock2: SELECT * FROM multixact_conflict FOR SHARE; <waiting ...>
+step s1_commit: COMMIT;
+step s2_tuplock2: <... completed>
+a              
+
+1              
+
+starting permutation: s1_begin s1_lcksvpt s1_tuplock3 s2_tuplock3 s1_commit
+step s1_begin: BEGIN;
+step s1_lcksvpt: SELECT * FROM multixact_conflict FOR KEY SHARE; SAVEPOINT foo;
+a              
+
+1              
+step s1_tuplock3: SELECT * FROM multixact_conflict FOR NO KEY UPDATE;
+a              
+
+1              
+step s2_tuplock3: SELECT * FROM multixact_conflict FOR NO KEY UPDATE; <waiting ...>
+step s1_commit: COMMIT;
+step s2_tuplock3: <... completed>
+a              
+
+1              
+
+starting permutation: s1_begin s1_lcksvpt s1_tuplock3 s2_tuplock4 s1_commit
+step s1_begin: BEGIN;
+step s1_lcksvpt: SELECT * FROM multixact_conflict FOR KEY SHARE; SAVEPOINT foo;
+a              
+
+1              
+step s1_tuplock3: SELECT * FROM multixact_conflict FOR NO KEY UPDATE;
+a              
+
+1              
+step s2_tuplock4: SELECT * FROM multixact_conflict FOR UPDATE; <waiting ...>
+step s1_commit: COMMIT;
+step s2_tuplock4: <... completed>
+a              
+
+1              
+
+starting permutation: s1_begin s1_lcksvpt s1_tuplock4 s2_tuplock1 s1_commit
+step s1_begin: BEGIN;
+step s1_lcksvpt: SELECT * FROM multixact_conflict FOR KEY SHARE; SAVEPOINT foo;
+a              
+
+1              
+step s1_tuplock4: SELECT * FROM multixact_conflict FOR UPDATE;
+a              
+
+1              
+step s2_tuplock1: SELECT * FROM multixact_conflict FOR KEY SHARE; <waiting ...>
+step s1_commit: COMMIT;
+step s2_tuplock1: <... completed>
+a              
+
+1              
+
+starting permutation: s1_begin s1_lcksvpt s1_tuplock4 s2_tuplock2 s1_commit
+step s1_begin: BEGIN;
+step s1_lcksvpt: SELECT * FROM multixact_conflict FOR KEY SHARE; SAVEPOINT foo;
+a              
+
+1              
+step s1_tuplock4: SELECT * FROM multixact_conflict FOR UPDATE;
+a              
+
+1              
+step s2_tuplock2: SELECT * FROM multixact_conflict FOR SHARE; <waiting ...>
+step s1_commit: COMMIT;
+step s2_tuplock2: <... completed>
+a              
+
+1              
+
+starting permutation: s1_begin s1_lcksvpt s1_tuplock4 s2_tuplock3 s1_commit
+step s1_begin: BEGIN;
+step s1_lcksvpt: SELECT * FROM multixact_conflict FOR KEY SHARE; SAVEPOINT foo;
+a              
+
+1              
+step s1_tuplock4: SELECT * FROM multixact_conflict FOR UPDATE;
+a              
+
+1              
+step s2_tuplock3: SELECT * FROM multixact_conflict FOR NO KEY UPDATE; <waiting ...>
+step s1_commit: COMMIT;
+step s2_tuplock3: <... completed>
+a              
+
+1              
+
+starting permutation: s1_begin s1_lcksvpt s1_tuplock4 s2_tuplock4 s1_commit
+step s1_begin: BEGIN;
+step s1_lcksvpt: SELECT * FROM multixact_conflict FOR KEY SHARE; SAVEPOINT foo;
+a              
+
+1              
+step s1_tuplock4: SELECT * FROM multixact_conflict FOR UPDATE;
+a              
+
+1              
+step s2_tuplock4: SELECT * FROM multixact_conflict FOR UPDATE; <waiting ...>
+step s1_commit: COMMIT;
+step s2_tuplock4: <... completed>
+a              
+
+1              
+
+starting permutation: s1_begin s1_tuplock1 s2_tuplock1 s1_commit
+step s1_begin: BEGIN;
+step s1_tuplock1: SELECT * FROM multixact_conflict FOR KEY SHARE;
+a              
+
+1              
+step s2_tuplock1: SELECT * FROM multixact_conflict FOR KEY SHARE;
+a              
+
+1              
+step s1_commit: COMMIT;
+
+starting permutation: s1_begin s1_tuplock1 s2_tuplock2 s1_commit
+step s1_begin: BEGIN;
+step s1_tuplock1: SELECT * FROM multixact_conflict FOR KEY SHARE;
+a              
+
+1              
+step s2_tuplock2: SELECT * FROM multixact_conflict FOR SHARE;
+a              
+
+1              
+step s1_commit: COMMIT;
+
+starting permutation: s1_begin s1_tuplock1 s2_tuplock3 s1_commit
+step s1_begin: BEGIN;
+step s1_tuplock1: SELECT * FROM multixact_conflict FOR KEY SHARE;
+a              
+
+1              
+step s2_tuplock3: SELECT * FROM multixact_conflict FOR NO KEY UPDATE;
+a              
+
+1              
+step s1_commit: COMMIT;
+
+starting permutation: s1_begin s1_tuplock1 s2_tuplock4 s1_commit
+step s1_begin: BEGIN;
+step s1_tuplock1: SELECT * FROM multixact_conflict FOR KEY SHARE;
+a              
+
+1              
+step s2_tuplock4: SELECT * FROM multixact_conflict FOR UPDATE; <waiting ...>
+step s1_commit: COMMIT;
+step s2_tuplock4: <... completed>
+a              
+
+1              
+
+starting permutation: s1_begin s1_tuplock2 s2_tuplock1 s1_commit
+step s1_begin: BEGIN;
+step s1_tuplock2: SELECT * FROM multixact_conflict FOR SHARE;
+a              
+
+1              
+step s2_tuplock1: SELECT * FROM multixact_conflict FOR KEY SHARE;
+a              
+
+1              
+step s1_commit: COMMIT;
+
+starting permutation: s1_begin s1_tuplock2 s2_tuplock2 s1_commit
+step s1_begin: BEGIN;
+step s1_tuplock2: SELECT * FROM multixact_conflict FOR SHARE;
+a              
+
+1              
+step s2_tuplock2: SELECT * FROM multixact_conflict FOR SHARE;
+a              
+
+1              
+step s1_commit: COMMIT;
+
+starting permutation: s1_begin s1_tuplock2 s2_tuplock3 s1_commit
+step s1_begin: BEGIN;
+step s1_tuplock2: SELECT * FROM multixact_conflict FOR SHARE;
+a              
+
+1              
+step s2_tuplock3: SELECT * FROM multixact_conflict FOR NO KEY UPDATE; <waiting ...>
+step s1_commit: COMMIT;
+step s2_tuplock3: <... completed>
+a              
+
+1              
+
+starting permutation: s1_begin s1_tuplock2 s2_tuplock4 s1_commit
+step s1_begin: BEGIN;
+step s1_tuplock2: SELECT * FROM multixact_conflict FOR SHARE;
+a              
+
+1              
+step s2_tuplock4: SELECT * FROM multixact_conflict FOR UPDATE; <waiting ...>
+step s1_commit: COMMIT;
+step s2_tuplock4: <... completed>
+a              
+
+1              
+
+starting permutation: s1_begin s1_tuplock3 s2_tuplock1 s1_commit
+step s1_begin: BEGIN;
+step s1_tuplock3: SELECT * FROM multixact_conflict FOR NO KEY UPDATE;
+a              
+
+1              
+step s2_tuplock1: SELECT * FROM multixact_conflict FOR KEY SHARE;
+a              
+
+1              
+step s1_commit: COMMIT;
+
+starting permutation: s1_begin s1_tuplock3 s2_tuplock2 s1_commit
+step s1_begin: BEGIN;
+step s1_tuplock3: SELECT * FROM multixact_conflict FOR NO KEY UPDATE;
+a              
+
+1              
+step s2_tuplock2: SELECT * FROM multixact_conflict FOR SHARE; <waiting ...>
+step s1_commit: COMMIT;
+step s2_tuplock2: <... completed>
+a              
+
+1              
+
+starting permutation: s1_begin s1_tuplock3 s2_tuplock3 s1_commit
+step s1_begin: BEGIN;
+step s1_tuplock3: SELECT * FROM multixact_conflict FOR NO KEY UPDATE;
+a              
+
+1              
+step s2_tuplock3: SELECT * FROM multixact_conflict FOR NO KEY UPDATE; <waiting ...>
+step s1_commit: COMMIT;
+step s2_tuplock3: <... completed>
+a              
+
+1              
+
+starting permutation: s1_begin s1_tuplock3 s2_tuplock4 s1_commit
+step s1_begin: BEGIN;
+step s1_tuplock3: SELECT * FROM multixact_conflict FOR NO KEY UPDATE;
+a              
+
+1              
+step s2_tuplock4: SELECT * FROM multixact_conflict FOR UPDATE; <waiting ...>
+step s1_commit: COMMIT;
+step s2_tuplock4: <... completed>
+a              
+
+1              
+
+starting permutation: s1_begin s1_tuplock4 s2_tuplock1 s1_commit
+step s1_begin: BEGIN;
+step s1_tuplock4: SELECT * FROM multixact_conflict FOR UPDATE;
+a              
+
+1              
+step s2_tuplock1: SELECT * FROM multixact_conflict FOR KEY SHARE; <waiting ...>
+step s1_commit: COMMIT;
+step s2_tuplock1: <... completed>
+a              
+
+1              
+
+starting permutation: s1_begin s1_tuplock4 s2_tuplock2 s1_commit
+step s1_begin: BEGIN;
+step s1_tuplock4: SELECT * FROM multixact_conflict FOR UPDATE;
+a              
+
+1              
+step s2_tuplock2: SELECT * FROM multixact_conflict FOR SHARE; <waiting ...>
+step s1_commit: COMMIT;
+step s2_tuplock2: <... completed>
+a              
+
+1              
+
+starting permutation: s1_begin s1_tuplock4 s2_tuplock3 s1_commit
+step s1_begin: BEGIN;
+step s1_tuplock4: SELECT * FROM multixact_conflict FOR UPDATE;
+a              
+
+1              
+step s2_tuplock3: SELECT * FROM multixact_conflict FOR NO KEY UPDATE; <waiting ...>
+step s1_commit: COMMIT;
+step s2_tuplock3: <... completed>
+a              
+
+1              
+
+starting permutation: s1_begin s1_tuplock4 s2_tuplock4 s1_commit
+step s1_begin: BEGIN;
+step s1_tuplock4: SELECT * FROM multixact_conflict FOR UPDATE;
+a              
+
+1              
+step s2_tuplock4: SELECT * FROM multixact_conflict FOR UPDATE; <waiting ...>
+step s1_commit: COMMIT;
+step s2_tuplock4: <... completed>
+a              
+
+1              
diff --git a/src/test/isolation/isolation_schedule b/src/test/isolation/isolation_schedule
index 1e73b4aebd7..60479c47fad 100644
--- a/src/test/isolation/isolation_schedule
+++ b/src/test/isolation/isolation_schedule
@@ -22,5 +22,6 @@ test: aborted-keyrevoke
 test: multixact-no-deadlock
 test: multixact-no-forget
 test: propagate-lock-delete
+test: tuplelock-conflict
 test: drop-index-concurrently-1
 test: timeouts
diff --git a/src/test/isolation/specs/tuplelock-conflict.spec b/src/test/isolation/specs/tuplelock-conflict.spec
new file mode 100644
index 00000000000..922b572f2d7
--- /dev/null
+++ b/src/test/isolation/specs/tuplelock-conflict.spec
@@ -0,0 +1,63 @@
+# Here we verify that tuple lock levels conform to their documented
+# conflict tables.
+
+setup {
+	DROP TABLE IF EXISTS multixact_conflict;
+	CREATE TABLE multixact_conflict (a int primary key);
+	INSERT INTO multixact_conflict VALUES (1);
+}
+
+teardown {
+	DROP TABLE multixact_conflict;
+}
+
+session "s1"
+step "s1_begin" { BEGIN; }
+step "s1_lcksvpt" { SELECT * FROM multixact_conflict FOR KEY SHARE; SAVEPOINT foo; }
+step "s1_tuplock1" { SELECT * FROM multixact_conflict FOR KEY SHARE; }
+step "s1_tuplock2" { SELECT * FROM multixact_conflict FOR SHARE; }
+step "s1_tuplock3" { SELECT * FROM multixact_conflict FOR NO KEY UPDATE; }
+step "s1_tuplock4" { SELECT * FROM multixact_conflict FOR UPDATE; }
+step "s1_commit" { COMMIT; }
+
+session "s2"
+step "s2_tuplock1" { SELECT * FROM multixact_conflict FOR KEY SHARE; }
+step "s2_tuplock2" { SELECT * FROM multixact_conflict FOR SHARE; }
+step "s2_tuplock3" { SELECT * FROM multixact_conflict FOR NO KEY UPDATE; }
+step "s2_tuplock4" { SELECT * FROM multixact_conflict FOR UPDATE; }
+
+# The version with savepoints test the multixact cases
+permutation "s1_begin" "s1_lcksvpt" "s1_tuplock1" "s2_tuplock1" "s1_commit"
+permutation "s1_begin" "s1_lcksvpt" "s1_tuplock1" "s2_tuplock2" "s1_commit"
+permutation "s1_begin" "s1_lcksvpt" "s1_tuplock1" "s2_tuplock3" "s1_commit"
+permutation "s1_begin" "s1_lcksvpt" "s1_tuplock1" "s2_tuplock4" "s1_commit"
+permutation "s1_begin" "s1_lcksvpt" "s1_tuplock2" "s2_tuplock1" "s1_commit"
+permutation "s1_begin" "s1_lcksvpt" "s1_tuplock2" "s2_tuplock2" "s1_commit"
+permutation "s1_begin" "s1_lcksvpt" "s1_tuplock2" "s2_tuplock3" "s1_commit"
+permutation "s1_begin" "s1_lcksvpt" "s1_tuplock2" "s2_tuplock4" "s1_commit"
+permutation "s1_begin" "s1_lcksvpt" "s1_tuplock3" "s2_tuplock1" "s1_commit"
+permutation "s1_begin" "s1_lcksvpt" "s1_tuplock3" "s2_tuplock2" "s1_commit"
+permutation "s1_begin" "s1_lcksvpt" "s1_tuplock3" "s2_tuplock3" "s1_commit"
+permutation "s1_begin" "s1_lcksvpt" "s1_tuplock3" "s2_tuplock4" "s1_commit"
+permutation "s1_begin" "s1_lcksvpt" "s1_tuplock4" "s2_tuplock1" "s1_commit"
+permutation "s1_begin" "s1_lcksvpt" "s1_tuplock4" "s2_tuplock2" "s1_commit"
+permutation "s1_begin" "s1_lcksvpt" "s1_tuplock4" "s2_tuplock3" "s1_commit"
+permutation "s1_begin" "s1_lcksvpt" "s1_tuplock4" "s2_tuplock4" "s1_commit"
+
+# no multixacts here
+permutation "s1_begin"              "s1_tuplock1" "s2_tuplock1" "s1_commit"
+permutation "s1_begin"              "s1_tuplock1" "s2_tuplock2" "s1_commit"
+permutation "s1_begin"              "s1_tuplock1" "s2_tuplock3" "s1_commit"
+permutation "s1_begin"              "s1_tuplock1" "s2_tuplock4" "s1_commit"
+permutation "s1_begin"              "s1_tuplock2" "s2_tuplock1" "s1_commit"
+permutation "s1_begin"              "s1_tuplock2" "s2_tuplock2" "s1_commit"
+permutation "s1_begin"              "s1_tuplock2" "s2_tuplock3" "s1_commit"
+permutation "s1_begin"              "s1_tuplock2" "s2_tuplock4" "s1_commit"
+permutation "s1_begin"              "s1_tuplock3" "s2_tuplock1" "s1_commit"
+permutation "s1_begin"              "s1_tuplock3" "s2_tuplock2" "s1_commit"
+permutation "s1_begin"              "s1_tuplock3" "s2_tuplock3" "s1_commit"
+permutation "s1_begin"              "s1_tuplock3" "s2_tuplock4" "s1_commit"
+permutation "s1_begin"              "s1_tuplock4" "s2_tuplock1" "s1_commit"
+permutation "s1_begin"              "s1_tuplock4" "s2_tuplock2" "s1_commit"
+permutation "s1_begin"              "s1_tuplock4" "s2_tuplock3" "s1_commit"
+permutation "s1_begin"              "s1_tuplock4" "s2_tuplock4" "s1_commit"