diff --git a/src/tja2fumen/parsers.py b/src/tja2fumen/parsers.py
index 9aacaa3..0049bdd 100644
--- a/src/tja2fumen/parsers.py
+++ b/src/tja2fumen/parsers.py
@@ -52,13 +52,15 @@ def split_tja_lines_into_courses(lines):
 
             # Course-specific header fields
             elif name_upper == 'COURSE':
+                if value not in NORMALIZE_COURSE.keys():
+                    raise ValueError(f"Invalid COURSE value: '{value}'")
                 current_course = NORMALIZE_COURSE[value]
                 current_course_cached = current_course
-                if current_course not in parsed_tja.courses.keys():
-                    raise ValueError()
             elif name_upper == 'LEVEL':
-                parsed_tja.courses[current_course].level = \
-                    int(value) if value else 0
+                if value not in ['1', '2', '3', '4', '5',
+                                 '6', '7', '8', '9', '10']:
+                    raise ValueError(f"Invalid LEVEL value: '{value}")
+                parsed_tja.courses[current_course].level = int(value)
             elif name_upper == 'SCOREINIT':
                 parsed_tja.courses[current_course].score_init = \
                     int(value.split(",")[-1]) if value else 0
diff --git a/testing/data/dummy_tjas/missing_course.tja b/testing/data/dummy_tjas/missing_course.tja
new file mode 100644
index 0000000..78ac3a3
--- /dev/null
+++ b/testing/data/dummy_tjas/missing_course.tja
@@ -0,0 +1,17 @@
+// This song contains only basic notes.
+BPM:120
+OFFSET:-1.00
+
+COURSE:
+LEVEL:10
+BALLOON:8,8
+SCOREINIT:400
+SCOREDIFF:100
+
+#START
+1020304,
+5000008,
+6000008,
+7000008,
+9000008,
+#END
diff --git a/testing/data/dummy_tjas/missing_level.tja b/testing/data/dummy_tjas/missing_level.tja
new file mode 100644
index 0000000..46dee92
--- /dev/null
+++ b/testing/data/dummy_tjas/missing_level.tja
@@ -0,0 +1,17 @@
+// This song contains only basic notes.
+BPM:120
+OFFSET:-1.00
+
+COURSE:Oni
+LEVEL:
+BALLOON:8,8
+SCOREINIT:400
+SCOREDIFF:100
+
+#START
+1020304,
+5000008,
+6000008,
+7000008,
+9000008,
+#END
diff --git a/testing/data/dummy_tjas/missing_score.tja b/testing/data/dummy_tjas/missing_score.tja
new file mode 100644
index 0000000..e15349d
--- /dev/null
+++ b/testing/data/dummy_tjas/missing_score.tja
@@ -0,0 +1,17 @@
+// This song is missing `SCOREINIT:` and `SCOREDIFF:` metadata
+BPM:120
+OFFSET:-1.00
+
+COURSE:Oni
+LEVEL:10
+BALLOON:8,8
+SCOREINIT:
+SCOREDIFF:
+
+#START
+1020304,
+5000008,
+6000008,
+7000008,
+9000008,
+#END
diff --git a/testing/test_command_support.py b/testing/test_command_support.py
index 7af7d07..7943867 100644
--- a/testing/test_command_support.py
+++ b/testing/test_command_support.py
@@ -8,7 +8,10 @@ from conftest import convert
 
 @pytest.mark.parametrize('id_song,err_msg', [
     ['basic_song', None],
-    ['missing_balloon', "Not enough values for 'BALLOON:"]
+    ['missing_score', None],
+    ['missing_balloon', "Not enough values for 'BALLOON:"],
+    ['missing_course', "Invalid COURSE value:"],
+    ['missing_level', "Invalid LEVEL value:"]
 ])
 def test_expected_errors(id_song, err_msg, tmp_path, entry_point):
     # Define the testing directory