diff --git a/src/piracy.test.c b/src/piracy.test.c
index dee326980..419f73073 100644
--- a/src/piracy.test.c
+++ b/src/piracy.test.c
@@ -47,6 +47,7 @@ static void setup_pirate(unit **pirate, int p_r_flags, int p_rc_flags, const cha
     if (v_shiptype) {
         st_boat = st_get_or_create(v_shiptype);
         u_set_ship(*victim, test_create_ship((*victim)->region, st_boat));
+        free(st_boat->coasts);
         st_boat->coasts = (struct terrain_type **)calloc(2, sizeof(struct terrain_type *));
         st_boat->coasts[0] = vterrain;
         st_boat->coasts[1] = 0;
@@ -59,6 +60,7 @@ static void setup_pirate(unit **pirate, int p_r_flags, int p_rc_flags, const cha
     if (p_shiptype) {
         st_boat = st_get_or_create(p_shiptype);
         u_set_ship(*pirate, test_create_ship((*pirate)->region, st_boat));
+        free(st_boat->coasts);
         st_boat->coasts = (struct terrain_type **)calloc(2, sizeof(struct terrain_type *));
         st_boat->coasts[0] = vterrain;
         st_boat->coasts[1] = 0;