diff --git a/src/study.c b/src/study.c
index a39f2e57b..aeb27b89d 100644
--- a/src/study.c
+++ b/src/study.c
@@ -848,12 +848,13 @@ bool learn_skill_depr(unit * u, skill_t sk, double learn_chance)
 
 void learn_skill(unit *u, skill_t sk, int days) {
     skill *sv = u->skills;
+    int leveldays = STUDYDAYS * u->number;
     int weeks = 0;
-    while (days >= STUDYDAYS) {
+    while (days >= leveldays) {
         ++weeks;
-        days -= STUDYDAYS;
+        days -= leveldays;
     }
-    if (days > 0 && rng_int() % STUDYDAYS < days) {
+    if (days > 0 && rng_int() % leveldays < days) {
         ++weeks;
     }
     if (weeks > 0 && !sv) {
diff --git a/src/study.test.c b/src/study.test.c
index 68989f91a..eaaafdc79 100644
--- a/src/study.test.c
+++ b/src/study.test.c
@@ -234,6 +234,7 @@ void test_learn_skill_single(CuTest *tc) {
     unit *u;
     skill *sv;
     test_cleanup();
+    config_set("study.random_progress", "0");
     u = test_create_unit(test_create_faction(0), test_create_region(0, 0, 0));
     learn_skill(u, SK_ALCHEMY, STUDYDAYS);
     CuAssertPtrNotNull(tc, sv = u->skills);
@@ -244,7 +245,7 @@ void test_learn_skill_single(CuTest *tc) {
     CuAssertIntEquals(tc, 1, sv->weeks);
     learn_skill(u, SK_ALCHEMY, STUDYDAYS * 2);
     CuAssertIntEquals(tc, 2, sv->level);
-    CuAssertIntEquals(tc, 1, sv->weeks);
+    CuAssertIntEquals(tc, 2, sv->weeks);
     test_cleanup();
 }
 
@@ -252,7 +253,8 @@ void test_learn_skill_multi(CuTest *tc) {
     unit *u;
     skill *sv;
     test_cleanup();
-    u = test_create_unit(0, 0);
+    config_set("study.random_progress", "0");
+    u = test_create_unit(test_create_faction(0), test_create_region(0, 0, 0));
     scale_number(u, 10);
     learn_skill(u, SK_ALCHEMY, STUDYDAYS * u->number);
     CuAssertPtrNotNull(tc, sv = u->skills);
@@ -263,7 +265,7 @@ void test_learn_skill_multi(CuTest *tc) {
     CuAssertIntEquals(tc, 1, sv->weeks);
     learn_skill(u, SK_ALCHEMY, STUDYDAYS  * u->number * 2);
     CuAssertIntEquals(tc, 2, sv->level);
-    CuAssertIntEquals(tc, 1, sv->weeks);
+    CuAssertIntEquals(tc, 2, sv->weeks);
     test_cleanup();
 }
 
diff --git a/src/tests.c b/src/tests.c
index c03680baf..2386fe08d 100644
--- a/src/tests.c
+++ b/src/tests.c
@@ -77,9 +77,9 @@ struct faction *test_create_faction(const struct race *rc)
 struct unit *test_create_unit(struct faction *f, struct region *r)
 {
     const struct race * rc = f ? f->race : 0;
-    assert(f);
+    assert(f || !r);
     if (!rc) rc = rc_get_or_create("human");
-    return create_unit(r, f, 1, rc, 0, 0, 0);
+    return create_unit(r, f, 1, rc ? rc : rc_get_or_create("human"), 0, 0, 0);
 }
 
 void test_cleanup(void)