diff --git a/src/kernel/ship.c b/src/kernel/ship.c
index a2a384383..dfb840179 100644
--- a/src/kernel/ship.c
+++ b/src/kernel/ship.c
@@ -300,7 +300,7 @@ int crew_skill(const ship *sh) {
 
 int shipspeed(const ship * sh, const unit * u)
 {
-    double k = sh->type->range;
+    int k = sh->type->range;
     static const struct curse_type *stormwind_ct, *nodrift_ct;
     static bool init;
     attrib *a;
@@ -344,7 +344,7 @@ int shipspeed(const ship * sh, const unit * u)
 
     c = get_curse(sh->attribs, ct_find("shipspeedup"));
     while (c) {
-        k += curse_geteffect(c);
+        k += curse_geteffect_int(c);
         c = c->nexthash;
     }
 
@@ -352,12 +352,12 @@ int shipspeed(const ship * sh, const unit * u)
     k *= SHIPSPEED;
 #endif
 
-    if (sh->damage)
-        k =
-        (k * (sh->size * DAMAGE_SCALE - sh->damage) + sh->size * DAMAGE_SCALE -
-        1) / (sh->size * DAMAGE_SCALE);
-
-    return (int)k;
+    if (sh->damage>0) {
+        int size = sh->size * DAMAGE_SCALE;
+        k *= (size - sh->damage);
+        k = (k + size - 1) / size;
+    }
+    return k;
 }
 
 const char *shipname(const ship * sh)
diff --git a/src/kernel/ship.test.c b/src/kernel/ship.test.c
index 21e6a9693..05a735d26 100644
--- a/src/kernel/ship.test.c
+++ b/src/kernel/ship.test.c
@@ -505,15 +505,12 @@ static void test_shipspeed_race_bonus(CuTest *tc) {
 static void test_shipspeed_damage(CuTest *tc) {
     ship *sh;
     unit *cap, *crew;
-    race *rc;
 
     test_cleanup();
     sh = setup_ship();
     setup_crew(sh, 0, &cap, &crew);
     assert(sh && cap && crew);
 
-    rc = rc_get_or_create(cap->_race->_name);
-    rc->flags |= RCF_SHIPSPEED;
     sh->damage = 1;
     CuAssertIntEquals_Msg(tc, "minimally damaged ships lose no range", 2, shipspeed(sh, cap));
     sh->damage = sh->size * DAMAGE_SCALE / 2;