diff --git a/src/services/scheduler_service.py b/src/services/scheduler_service.py
index a2e8dac..455d749 100644
--- a/src/services/scheduler_service.py
+++ b/src/services/scheduler_service.py
@@ -59,8 +59,8 @@ def max_credits(self) -> int:
 
     @max_credits.setter
     def max_credits(self, max_credits: int) -> None:
-        if max_credits < 0:
-            raise MaxCreditError("Opintopisteyläraja ei voi olla negatiivinen.")
+        if max_credits <= 0:
+            raise MaxCreditError("Opintopisteyläraja ei voi olla ei-positiivinen.")
 
         for course in self.__courses.values():
             if course.credits > max_credits:
diff --git a/src/tests/services/test_scheduler_service.py b/src/tests/services/test_scheduler_service.py
index ff3109c..93f627a 100644
--- a/src/tests/services/test_scheduler_service.py
+++ b/src/tests/services/test_scheduler_service.py
@@ -60,9 +60,13 @@ def test_max_credits(self):
         scheduler = SchedulerService(courses)
 
         scheduler.max_credits = 3
-        scheduler.max_credits = 2
+        scheduler.max_credits = 4
+        scheduler.max_credits = 100
+
+    def test_max_credits_with_non_positive_value_raises_error(self):
+        with self.assertRaises(MaxCreditError):
+            self.scheduler.max_credits = 0
 
-    def test_negative_max_credits_raises_error(self):
         with self.assertRaises(MaxCreditError):
             self.scheduler.max_credits = -10