diff --git a/ci/emscripten.sh b/ci/emscripten.sh
index 2e87130e0507556a84e28e2e1e90ac7393eacb8f..e5272728425081da7748ff2f4c2d36b2ff54a31b 100644
--- a/ci/emscripten.sh
+++ b/ci/emscripten.sh
@@ -23,8 +23,8 @@ git clone https://github.com/emscripten-core/emsdk.git /emsdk-portable
 cd /emsdk-portable
 # FIXME: switch to an upstream install once
 # https://github.com/rust-lang/rust/pull/63649 lands
-hide_output ./emsdk install 1.38.42
-./emsdk activate 1.38.42
+hide_output ./emsdk install 1.39.12
+./emsdk activate 1.39.12
 
 # Compile and cache libc
 # shellcheck disable=SC1091