diff --git a/.github/workflows/reusable-wasi.yml b/.github/workflows/reusable-wasi.yml
index b0dda62d0b291c2..fd263e8aafd8f58 100644
--- a/.github/workflows/reusable-wasi.yml
+++ b/.github/workflows/reusable-wasi.yml
@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-26.04-arm
     timeout-minutes: 60
     env:
-      WASMTIME_VERSION: 38.0.3
+      WASMTIME_VERSION: 48.0.2
       CROSS_BUILD_WASI: cross-build/wasm32-wasip1
     steps:
     - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
diff --git a/Misc/NEWS.d/next/Build/2026-09-21-10-50-31.gh-issue-157923.OffPYn.rst b/Misc/NEWS.d/next/Build/2026-09-21-10-50-31.gh-issue-157923.OffPYn.rst
new file mode 100644
index 000000000000000..f1126adb1a069e6
--- /dev/null
+++ b/Misc/NEWS.d/next/Build/2026-09-21-10-50-31.gh-issue-157923.OffPYn.rst
@@ -0,0 +1 @@
+Support WASI SDK 34.
diff --git a/Platforms/WASI/config.site-wasm32-wasi b/Platforms/WASI/config.site-wasm32-wasi
index c5d8b3e205db26f..88c54907880e73b 100644
--- a/Platforms/WASI/config.site-wasm32-wasi
+++ b/Platforms/WASI/config.site-wasm32-wasi
@@ -57,3 +57,7 @@ ac_cv_func_fchmod=no
 ac_cv_func_fchmodat=no
 ac_cv_func_statvfs=no
 ac_cv_func_fstatvfs=no
+
+# WASI SDK 34 declares some things that simply error out.
+ac_cv_func_pipe2=no
+ac_cv_func_pthread_getcpuclockid=no
diff --git a/Platforms/WASI/config.toml b/Platforms/WASI/config.toml
index 6a6d5713ee96739..151c528c87670d5 100644
--- a/Platforms/WASI/config.toml
+++ b/Platforms/WASI/config.toml
@@ -2,5 +2,5 @@
 # This allows for blanket copying of the WASI build code between supported
 # Python versions.
 [targets]
-wasi-sdk = 33
+wasi-sdk = 34
 host-triple = "wasm32-wasip1"