diff --git a/tests/scripts/analyze_outcomes.py b/tests/scripts/analyze_outcomes.py
index 5193a3b..9c13d8c 100755
--- a/tests/scripts/analyze_outcomes.py
+++ b/tests/scripts/analyze_outcomes.py
@@ -85,6 +85,15 @@
 def analyze_coverage(results: Results, outcomes: Outcomes,
                      allow_list: typing.List[str], full_coverage: bool) -> None:
     """Check that all available test cases are executed at least once."""
+    # Make sure that the generated data files are present (and up-to-date).
+    # This allows analyze_outcomes.py to run correctly on a fresh Git
+    # checkout.
+    cp = subprocess.run(['make', 'generated_files'],
+                        cwd='tests',
+                        stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
+    if cp.returncode != 0:
+        sys.stderr.write(cp.stdout.decode('utf-8'))
+        results.error("Failed \"make generated_files\" in tests. Coverage analysis may be incorrect.")
     available = check_test_cases.collect_available_test_cases()
     for suite_case in available:
         hit = any(suite_case in comp_outcomes.successes or