diff --git a/public/challenge/2024/dockerfiles/mznc2024/Dockerfile b/public/challenge/2024/dockerfiles/mznc2024/Dockerfile
index 6c8054df1..2435b8df9 100644
--- a/public/challenge/2024/dockerfiles/mznc2024/Dockerfile
+++ b/public/challenge/2024/dockerfiles/mznc2024/Dockerfile
@@ -178,8 +178,8 @@ RUN \
 #------------------------------------------------------------------------------#
 # Setup of the base image
 
-# Get base image with Ubuntu 20.04
-FROM minizinc/minizinc:2.8.4-focal
+# Get base image with Ubuntu 22.04
+FROM minizinc/minizinc:2.8.5-jammy
 
 # Copy unpacked MiniZinc installation from the build image
 COPY --from=builder /minizinc /minizinc
diff --git a/src/data/challenge/info.js b/src/data/challenge/info.js
index 601a5a8c0..89d85e0db 100644
--- a/src/data/challenge/info.js
+++ b/src/data/challenge/info.js
@@ -2,9 +2,12 @@ import { Link } from '@/components/Link'
 
 export const info = {
   2024: (() => {
-    const problemSubmissionDeadline = 'Fri, 7 June 2024'
+    const problemSubmissionDeadline = 'Fri, 28 June 2024'
     return {
       announcements: [
+        <>
+          <strong>2024-06-03</strong> Problem submission deadline extended.
+        </>,
         <>
           <strong>2024-02-12</strong> Official{' '}
           <Link href="/challenge/2024/call_for_problems">
@@ -14,13 +17,13 @@ export const info = {
         </>,
       ],
       problemSubmissionDeadline,
-      minizinc: '2.8.4',
+      minizinc: '2.8.5',
       dates: [
         <>
           Registration opens: <strong>Now</strong>.
         </>,
         <>
-          Problem submission deadline:{' '}
+          Problem submission deadline: <s>Fri, 7 June 2024</s>{' '}
           <strong>{problemSubmissionDeadline}</strong>.
         </>,
         <>
diff --git a/src/data/release.mdx b/src/data/release.mdx
index a33a3b565..a2ac7bb5a 100644
--- a/src/data/release.mdx
+++ b/src/data/release.mdx
@@ -1,18 +1,29 @@
 import { BugRef, IDEBugRef } from '@/components/BugRef'
 
-- Add `-w` and `--disable-warnings` flags that will suppress all warnings
-  emitted by the flattening process.
-- Add option for solver libraries to set `mzn_opt_annotate_computed_domains`
-  such that the compiler will signal domains that are enforced by separate
-  constraints using a `computed_domain` annotation.
-- Always output multidimensional arrays as nested arrays when using `showJSON`
-  for consistency.
-- Add missing implementation for `default` for sets expressions.
-- Add missing optional versions of unary mathematical functions/operators.
-- Improve special-case handling of boolean `<->` and `xor` operators.
-- Allow IDE MOOC submission window to be scrolled.
-- Increase IDE hard process termination timeout to 1s.
-- Plus more than 30 bugfixes.
+- Add `string_split` function that splits a string into an array of strings
+  based on a separator.
+- Add `json_section` annotation to mark an output item as a JSON section
+  (<BugRef issue={816} />).
+- Fix specification for constraint items and annotations in FlatZinc JSON.
+- Fix flattening of negated let expressions with constraints.
+- Fix crash when equating identifiers to tuples/records in if-then-else
+  expressions.
+- Fix `string_length` function to return the number of Unicode code points
+  rather than the number of bytes (i.e., to interpret the string as UTF-8).
+- Emit type error for opt tuples and records created through type aliases.
+- Fix evaluation of par partial functions returning arrays.
+- Fix type inference for if-then-else expressions with different tuple or
+  record types in the branches.
+- Fix evaluation error caused by removal of fixed FlatZinc variables without
+  fixing them in the output model.
+- Fix computed type when flattening cv comprehensions containing tuple or
+  record types.
+- Fix unsatisfiability caused by reification in negated boolean context
+  (<BugRef issue={813} />).
+- Fix bug in computation of common type of incompatible record types.
+- Fix crash when type checking nested arrays of tuples or records.
+- Fix incorrect unification of flattened tuple/record fields with paths
+  enabled.
 
 export default function Release({ children }) {
   return (
diff --git a/src/data/version.js b/src/data/version.js
index de576b245..5986e98bf 100644
--- a/src/data/version.js
+++ b/src/data/version.js
@@ -1,4 +1,5 @@
 const releaseList = [
+  ['2.8.5', '3 June 2024'],
   ['2.8.4', '10 May 2024'],
   ['2.8.3', '1 February 2024'],
   ['2.8.2', '15 December 2023'],
diff --git a/src/pages/challenge/2024/rules.mdx b/src/pages/challenge/2024/rules.mdx
index 314e3a1be..6bd2b037c 100644
--- a/src/pages/challenge/2024/rules.mdx
+++ b/src/pages/challenge/2024/rules.mdx
@@ -21,7 +21,7 @@ export const challenge = info[year]
 />
 
 These are the official rules for the MiniZinc Challenge {year}. Version 1.1.
-These rules were last updated on 10 May {year}.
+These rules were last updated on 3 June {year}.
 
 ### Solver submission
 
@@ -168,7 +168,7 @@ so that timing information is accurate.
 During the MiniZinc Challenge {year} all instances of Docker images will run on a compute server with
 the following specification:
 
-- Image Operating System: Ubuntu 20.04 LTS (focal)
+- Image Operating System: Ubuntu 22.04 LTS (Jammy Jellyfish)
 - Processor(s): Intel Xeon® Platinum 8260
 - Configuration for FD, FREE: 1 core, 16 GiB memory
 - Configuration for PAR, OPEN: 4 cores, 32 GiB memory