diff --git a/src/kernel/curse.test.c b/src/kernel/curse.test.c
index d7c86b9b0..0ca4510d9 100644
--- a/src/kernel/curse.test.c
+++ b/src/kernel/curse.test.c
@@ -5,6 +5,7 @@
 #include <kernel/save.h>
 #include <kernel/unit.h>
 #include <util/attrib.h>
+#include <util/rng.h>
 #include <util/gamedata.h>
 #include <util/message.h>
 #include <binarystore.h>
@@ -175,6 +176,43 @@ static void test_curse_cache(CuTest *tc)
     test_cleanup();
 }
 
+static void test_curse_ids(CuTest *tc) {
+    const curse_type ct_dummy = { "dummy", CURSETYP_NORM, 0, M_SUMEFFECT, NULL };
+    curse *c1, *c2;
+    attrib *a1 = 0, *a2 = 0;
+
+    test_setup();
+    rng_init(0);
+    c1 = create_curse(NULL, &a1, &ct_dummy, 1, 1, 1, 1);
+    rng_init(0);
+    c2 = create_curse(NULL, &a2, &ct_dummy, 1, 1, 1, 1);
+    CuAssertTrue(tc, c1->no != c2->no);
+    a_remove(&a1, a1);
+    a_remove(&a2, a2);
+    test_cleanup();
+}
+
+static void test_curse_flags(CuTest *tc) {
+    const curse_type ct_dummy = { "dummy", CURSETYP_NORM, 0, M_SUMEFFECT, NULL };
+    curse *c1, *c2;
+    unit *u;
+
+    test_setup();
+    u = test_create_unit(test_create_faction(0), test_create_region(0, 0, 0));
+    c1 = create_curse(u, &u->attribs, &ct_dummy, 1, 1, 1, 0);
+    CuAssertPtrEquals(tc, u, c1->magician);
+    CuAssertIntEquals(tc, 1, (int)c1->effect);
+    CuAssertIntEquals(tc, 1, (int)c1->vigour);
+    CuAssertIntEquals(tc, 1, c1->duration);
+    c2 = create_curse(u, &u->attribs, &ct_dummy, 1, 1, 1, 0);
+    CuAssertPtrEquals(tc, c1, c2);
+    CuAssertPtrEquals(tc, u, c1->magician);
+    CuAssertIntEquals(tc, 2, (int)c1->effect);
+    CuAssertIntEquals(tc, 1, (int)c1->vigour);
+    CuAssertIntEquals(tc, 1, c1->duration);
+    test_cleanup();
+}
+
 CuSuite *get_curse_suite(void)
 {
     CuSuite *suite = CuSuiteNew();
@@ -186,5 +224,7 @@ CuSuite *get_curse_suite(void)
     SUITE_ADD_TEST(suite, test_bad_dreams);
     SUITE_ADD_TEST(suite, test_memstream);
     SUITE_ADD_TEST(suite, test_write_flag);
+    SUITE_ADD_TEST(suite, test_curse_flags);
+    SUITE_ADD_TEST(suite, test_curse_ids);
     return suite;
 }
diff --git a/src/kernel/unit.c b/src/kernel/unit.c
index 201153663..ad8377254 100644
--- a/src/kernel/unit.c
+++ b/src/kernel/unit.c
@@ -1717,7 +1717,7 @@ void renumber_unit(unit *u, int no) {
     uunhash(u);
     if (!ualias(u)) {
         attrib *a = a_add(&u->attribs, a_new(&at_alias));
-        a->data.i = -u->no;
+        a->data.i = -u->no; // TODO: why is the alias negative? confusing!
     }
     u->no = no;
     uhash(u);
diff --git a/src/kernel/unit.test.c b/src/kernel/unit.test.c
index 054a45652..c4b1f46ed 100644
--- a/src/kernel/unit.test.c
+++ b/src/kernel/unit.test.c
@@ -8,9 +8,10 @@
 #include <kernel/race.h>
 #include <kernel/region.h>
 #include <kernel/spell.h>
+#include <util/attrib.h>
 #include <util/base36.h>
 #include <util/language.h>
-#include <util/attrib.h>
+#include <util/rng.h>
 #include <spells/regioncurse.h>
 #include <alchemy.h>
 #include <laws.h>
@@ -454,6 +455,19 @@ static void test_remove_unit(CuTest *tc) {
     test_cleanup();
 }
 
+static void test_renumber_unit(CuTest *tc) {
+    unit *u1, *u2;
+    test_setup();
+    u1 = test_create_unit(test_create_faction(0), test_create_region(0, 0, 0));
+    u2 = test_create_unit(u1->faction, u1->region);
+    rng_init(0);
+    renumber_unit(u1, 0);
+    rng_init(0);
+    renumber_unit(u2, 0);
+    CuAssertTrue(tc, u1->no != u2->no);
+    test_cleanup();
+}
+
 CuSuite *get_unit_suite(void)
 {
     CuSuite *suite = CuSuiteNew();
@@ -476,5 +490,6 @@ CuSuite *get_unit_suite(void)
     SUITE_ADD_TEST(suite, test_age_familiar);
     SUITE_ADD_TEST(suite, test_inside_building);
     SUITE_ADD_TEST(suite, test_limited_skills);
+    SUITE_ADD_TEST(suite, test_renumber_unit);
     return suite;
 }