diff --git a/sonar-project.properties b/sonar-project.properties
index 6e78dc7f7c..bf4496425f 100644
--- a/sonar-project.properties
+++ b/sonar-project.properties
@@ -1,2 +1,9 @@
 sonar.projectKey=storytold_wordcraft
 sonar.organization=storytold
+
+# S4790 (weak hash): SHA-1 is a start-key and "SHA1/1K" checksum algorithm that ODF package
+# encryption (ODF 1.3 Part 2 §4.16) names, and older office suites wrote it. It is needed to open
+# those files, not chosen for new security: WordCraft writes a SHA-256 start key and checksum.
+sonar.issue.ignore.multicriteria=odt_sha1
+sonar.issue.ignore.multicriteria.odt_sha1.ruleKey=rust:S4790
+sonar.issue.ignore.multicriteria.odt_sha1.resourceKey=crates/formats/src/odt/crypt.rs