diff --git a/src/main/resources/challenges/challenge-51/Dockerfile_challenge51 b/src/main/resources/challenges/challenge-51/Dockerfile_challenge51
index 55d5d7a5b5..ccbd4e5041 100644
--- a/src/main/resources/challenges/challenge-51/Dockerfile_challenge51
+++ b/src/main/resources/challenges/challenge-51/Dockerfile_challenge51
@@ -1,4 +1,4 @@
-# syntax=docker/dockerfile:1.24
+# syntax=docker/dockerfile:1.25
 FROM debian:stable-slim
 
 RUN --mount=type=secret,id=db_user \
diff --git a/src/main/resources/challenges/challenge-64/Dockerfile_challenge64 b/src/main/resources/challenges/challenge-64/Dockerfile_challenge64
index 5dc7dae922..12f9604900 100644
--- a/src/main/resources/challenges/challenge-64/Dockerfile_challenge64
+++ b/src/main/resources/challenges/challenge-64/Dockerfile_challenge64
@@ -1,4 +1,4 @@
-# syntax=docker/dockerfile:1.24
+# syntax=docker/dockerfile:1.25
 # Test that the wrongsecrets-swift musl binary runs correctly on Alpine.
 # The musl binaries are fully statically linked (Swift runtime embedded), so they
 # run natively on Alpine's musl libc without any extra shared libraries.