diff --git a/src/plugins/markdown-report/md_gen.ml b/src/plugins/markdown-report/md_gen.ml
index 98393b5a30960042e28c3ca9c5b2593cdc7e4e48..cf35c41074a83e232559379ba4875d6408cf90ee 100644
--- a/src/plugins/markdown-report/md_gen.ml
+++ b/src/plugins/markdown-report/md_gen.ml
@@ -447,7 +447,7 @@ let gen_section_alarms env =
             Text
               (plain
                  "The following ACSL assertion must hold to avoid \
-                  and undefined behavior ("
+                  an undefined behavior ("
                @ kind @ plain ")");
             descr
           ]