diff --git a/.bazelversion b/.bazelversion
index f22d756da..a3fcc7121 100644
--- a/.bazelversion
+++ b/.bazelversion
@@ -1 +1 @@
-6.5.0
+7.1.0
diff --git a/.github/workflows/workflow.yaml b/.github/workflows/workflow.yaml
index 845ef6450..1cc3a4a87 100644
--- a/.github/workflows/workflow.yaml
+++ b/.github/workflows/workflow.yaml
@@ -275,8 +275,8 @@ jobs:
         os: [ubuntu-24.04, macos-14, macos-15-intel, windows-2022]
         bzlmod: [true, false]
         bazel:
-          - "6.x"
           - "7.x"
+          # - "8.x"
         exclude:
           # TODO(cb) add full support for Bazel 7
           - os: windows-2022
diff --git a/haskell/ghc_bindist.bzl b/haskell/ghc_bindist.bzl
index 033207246..902211ad7 100644
--- a/haskell/ghc_bindist.bzl
+++ b/haskell/ghc_bindist.bzl
@@ -642,7 +642,7 @@ py_runtime_pair(
 toolchain(
     name = "toolchain",
     toolchain = ":py_runtime_pair",
-    toolchain_type = "@bazel_tools//tools/python:toolchain_type",
+    toolchain_type =  "@rules_python//python:toolchain_type",
     exec_compatible_with = [
         "@platforms//cpu:{cpu}",
         "@platforms//os:{os}",
diff --git a/haskell/private/versions.bzl b/haskell/private/versions.bzl
index cf090f681..d1b354d78 100644
--- a/haskell/private/versions.bzl
+++ b/haskell/private/versions.bzl
@@ -14,13 +14,10 @@
 # because every bazel version tested requires a lot of space on CI
 # See https://github.com/tweag/rules_haskell/pull/1781#issuecomment-1187640454
 SUPPORTED_BAZEL_VERSIONS = [
-    "6.3.2",
-    "6.5.0",
     "7.1.0",
 ]
 
 SUPPORTED_NIXPKGS_BAZEL_PACKAGES = [
-    "bazel_6",
     "bazel_7",
 ]
 
diff --git a/haskell/repositories.bzl b/haskell/repositories.bzl
index 7a1af3c44..d99777b52 100644
--- a/haskell/repositories.bzl
+++ b/haskell/repositories.bzl
@@ -76,9 +76,9 @@ def rules_haskell_dependencies():
     maybe(
         http_archive,
         name = "rules_java",
-        sha256 = "29ba147c583aaf5d211686029842c5278e12aaea86f66bd4a9eb5e525b7f2701",
+        sha256 = "8afd053dd2a7b85a4f033584f30a7f1666c5492c56c76e04eec4428bdb2a86cf",
         urls = [
-            "https://github.com/bazelbuild/rules_java/releases/download/6.3.0/rules_java-6.3.0.tar.gz",
+            "https://github.com/bazelbuild/rules_java/releases/download/7.6.5/rules_java-7.6.5.tar.gz",
         ],
     )
 
diff --git a/rules_haskell_tests/MODULE.bazel b/rules_haskell_tests/MODULE.bazel
index 1071d500a..f168552f2 100644
--- a/rules_haskell_tests/MODULE.bazel
+++ b/rules_haskell_tests/MODULE.bazel
@@ -128,10 +128,7 @@ non_modules_deps_1 = use_extension("//:non_module_deps_1.bzl", "non_module_deps_
 use_repo(
     non_modules_deps_1,
     "asterius_bundle_linux_amd64",
-    "bazel_6",
     "bazel_7",
-    "build_bazel_bazel_6_3_2",
-    "build_bazel_bazel_6_5_0",
     "build_bazel_bazel_7_1_0",
     "glibc_locales",
     "linux_amd64_asterius-toolchain",
diff --git a/rules_haskell_tests/shell.nix b/rules_haskell_tests/shell.nix
index 2bbf21c73..bcfa20b40 100644
--- a/rules_haskell_tests/shell.nix
+++ b/rules_haskell_tests/shell.nix
@@ -33,7 +33,7 @@ mkShell {
     file
   ] ++ lib.optionals docTools [ graphviz python3Packages.sphinx zip unzip ];
 
-  packages = [ bazel_6 ];
+  packages = [ bazel_7 ];
 
   shellHook = ''
     # Add nix config flags to .bazelrc.local.
diff --git a/rules_haskell_tests/tests/haskell_import/main.c b/rules_haskell_tests/tests/haskell_import/main.c
index 28624227d..6c8806260 100644
--- a/rules_haskell_tests/tests/haskell_import/main.c
+++ b/rules_haskell_tests/tests/haskell_import/main.c
@@ -5,7 +5,7 @@ extern HsInt add_one_hs(HsInt a0);
 
 int main(int argc, char *argv[]) {
   hs_init(&argc, &argv);
-  printf("Adding one to 5 through Haskell is %ld\n", add_one_hs(5));
+  printf("Adding one to 5 through Haskell is %" FMT_Int "\n", add_one_hs(5));
   hs_exit();
   return 0;
 }
diff --git a/shell.nix b/shell.nix
index 1a44395fe..ad9cd863e 100644
--- a/shell.nix
+++ b/shell.nix
@@ -42,7 +42,7 @@ mkShell {
   ++ lib.optionals docTools [ graphviz python3Packages.sphinx zip unzip ]
   ++ lib.optional stdenv.isDarwin macOS-security;
 
-  packages = [ bazel_6 ];
+  packages = [ bazel_7 ];
 
   shellHook = ''
     # Add nix config flags to .bazelrc.local.