diff --git a/dockerfiles/ci-tools/report_diff.py b/dockerfiles/ci-tools/report_diff.py
index 675bb6723fc826e951f2eddf249a1b683ed1f8d6..472343971f2d8d923e03ecd5944b6dfab928c8f1 100755
--- a/dockerfiles/ci-tools/report_diff.py
+++ b/dockerfiles/ci-tools/report_diff.py
@@ -6,12 +6,11 @@ from junitparser import JUnitXml, TestSuite
 
 
 def case_dictionary(report):
-    result = {}
-    for suite in report:
-        for case in suite:
-            key = (case.classname, case.name)
-            result[key] = case
-    return result
+    return {
+        (case.classname, case.name): case
+        for suite in report
+        for case in suite
+    }
 
 
 def compare_reports(path_before, path_after, path_out):