diff --git a/scripts/build-unit-test-docker b/scripts/build-unit-test-docker
index 739f74a..36ecb0f 100755
--- a/scripts/build-unit-test-docker
+++ b/scripts/build-unit-test-docker
@@ -107,7 +107,7 @@
         ],
     ),
     "fmtlib/fmt": PackageDef(
-        rev="8.1.1",
+        rev="9.1.0",
         build_type="cmake",
         config_flags=[
             "-DFMT_DOC=OFF",