diff --git a/app/models/similarity/unit_similarity_module.rb b/app/models/similarity/unit_similarity_module.rb
index e5f3144e7d..c003c36b56 100644
--- a/app/models/similarity/unit_similarity_module.rb
+++ b/app/models/similarity/unit_similarity_module.rb
@@ -306,7 +306,7 @@ def run_jplag_on_done_files(task_definition, tasks_dir, tasks_with_files, unit_c
     skip_cluster_string = skip_cluster_check ? '--cluster-skip' : ''
 
     # Run JPLAG on the extracted files. JPlag container should already be in the /jplag/ workdir.
-    docker_command = "docker exec -i jplag java -jar jplag-jar-with-dependencies.jar #{tasks_dir_split}/submissions #{base_code_string} -l #{file_lang} --similarity-threshold=#{similarity_threshold} #{min_token_string} #{skip_cluster_string} -M RUN -r #{results_dir}/#{task_definition.abbreviation}-result --overwrite"
+    docker_command = "docker exec -i jplag java -jar jplag-jar-with-dependencies.jar --skip-version-check #{tasks_dir_split}/submissions #{base_code_string} -l #{file_lang} --similarity-threshold=#{similarity_threshold} #{min_token_string} #{skip_cluster_string} -M RUN -r #{results_dir}/#{task_definition.abbreviation}-result --overwrite"
     logger.debug "Executing command: #{docker_command}"
     system(docker_command)
 
diff --git a/jplag.Dockerfile b/jplag.Dockerfile
index 58209c7eaa..1fcf747ce6 100644
--- a/jplag.Dockerfile
+++ b/jplag.Dockerfile
@@ -1,10 +1,10 @@
-FROM alpine:3.22.1
+FROM alpine:3.23.3
 
-ENV JPLAG_VERSION=6.2.0
+ENV JPLAG_VERSION=6.3.0
 WORKDIR /jplag
 
 RUN apk update && \
-  apk add --no-cache bash openjdk21 wget && \
+  apk add --no-cache bash openjdk25-jdk wget && \
   wget -O jplag-jar-with-dependencies.jar \
   https://github.com/jplag/JPlag/releases/download/v$JPLAG_VERSION/jplag-$JPLAG_VERSION-jar-with-dependencies.jar