diff --git a/info/Trade-ships.t b/info/Trade-ships.t
index 96aebbaf..8dd622bb 100644
--- a/info/Trade-ships.t
+++ b/info/Trade-ships.t
@@ -43,7 +43,7 @@ paid for it, or $2188. If you sailed it 15 sectors to a harbor and scuttled it,
 you would get 153%, or $2678.
 .s1
 Use the \*Qpayoff\*U command to see how much the trade ship would pay
-were it scuttled in a harbour at its present location.
+were it scuttled in a harbor at its present location.
 .s1
 If you scuttle a trade ship in the harbor you do not own, you get a 20% bonus
 (applied after the value is multiplied by the return rate above), AND the
diff --git a/info/relations.t b/info/relations.t
index 7f152103..0e47e013 100644
--- a/info/relations.t
+++ b/info/relations.t
@@ -46,7 +46,7 @@ allies, but not by others .  Allied nations are assumed to have
 .L Friendly
 When you accept a country as a trustworthy trading partner, then you
 establish friendly relations towards them.  This allows them to sail
-ships into your harbours, load and unload goods, and have their
+ships into your harbors, load and unload goods, and have their
 ships repaired there.  You are allowed to "tend" friendly
 ships.  You may send "flash" messages (see info flash) to friendly nations.
 You will be warned, however, if they overfly
diff --git a/info/scrap.t b/info/scrap.t
index a73d31a3..4469fb59 100644
--- a/info/scrap.t
+++ b/info/scrap.t
@@ -5,7 +5,7 @@
 This command allows you to scrap planes/units/ships when you no longer
 need them.
 .s1
-Ships may only be scrapped in own or friendly 60% harbours.
+Ships may only be scrapped in own or friendly 60% harbors.
 Planes may only be scrapped in own or allied 60% airfields.
 Land units may only be scrapped in own or allied sectors.
 .s1
diff --git a/info/unload.t b/info/unload.t
index cab387b6..f370e65e 100644
--- a/info/unload.t
+++ b/info/unload.t
@@ -12,6 +12,6 @@ The only thing to know is that unload won't unload more of a thing if the
 sector already has 999. For example, if a ship has 10 food, and the harbor
 has 994, you can only unload 5 of the 10 food.
 .s1
-Also, you must have Friendly relations with the owner of the harbour
+Also, you must have Friendly relations with the owner of the harbor
 in order to unload into it.
 .SA "load, Ships, Moving"
diff --git a/src/lib/commands/buil.c b/src/lib/commands/buil.c
index 96e8433d..b85177ae 100644
--- a/src/lib/commands/buil.c
+++ b/src/lib/commands/buil.c
@@ -216,7 +216,7 @@ build_ship(struct sctstr *sp, int type, int tlev)
     memcpy(mat, mp->m_mat, sizeof(mat));
 
     if (sp->sct_type != SCT_HARBR && !player->god) {
-	pr("Ships must be built in harbours.\n");
+	pr("Ships must be built in harbors.\n");
 	return 0;
     }
     if (!sector_can_build(sp, mat, mp->m_bwork, SHIP_MINEFF, mp->m_name))
diff --git a/tests/build/journal.log b/tests/build/journal.log
index 0ebbaa3a..825cbc42 100644
--- a/tests/build/journal.log
+++ b/tests/build/journal.log
@@ -57,7 +57,7 @@
     Play#1 output Play#1 6 0 636
     Play#1 input build s 0,0 pt
     Play#1 command build
-    Play#1 output Play#1 1 Ships must be built in harbours.
+    Play#1 output Play#1 1 Ships must be built in harbors.
     Play#1 output Play#1 6 0 635
     Play#1 input build s 4:6,0 pt
     Play#1 command build