diff --git a/dist/web/Dockerfile b/dist/web/Dockerfile
index e07056f8b..22b0f490f 100644
--- a/dist/web/Dockerfile
+++ b/dist/web/Dockerfile
@@ -1,4 +1,4 @@
-FROM emscripten/emsdk:3.1.51 as build
+FROM emscripten/emsdk:3.1.51 AS build
 
 # Used to invalidate layer cache but not mount cache
 # See https://github.com/moby/moby/issues/41715#issuecomment-733976493
@@ -27,7 +27,7 @@ set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -pthread")
 ' >> /emsdk/upstream/emscripten/cmake/Modules/Platform/Emscripten.cmake
 EOF
 
-ENV VCPKG_DEFAULT_BINARY_CACHE /cache/vcpkg
+ENV VCPKG_DEFAULT_BINARY_CACHE=/cache/vcpkg
 RUN --mount=type=cache,target=/cache <<EOF
 # Install dependencies with vcpkg
 set -xe
@@ -45,7 +45,7 @@ EOF
 
 # Build ImHex
 ARG JOBS=4
-ENV CCACHE_DIR /cache/ccache
+ENV CCACHE_DIR=/cache/ccache
 
 RUN mkdir /build
 WORKDIR /build
@@ -80,7 +80,7 @@ EOF
 # See https://stackoverflow.com/questions/41701849/cannot-modify-accept-encoding-with-fetch https://github.com/AnthumChris/fetch-progress-indicators/issues/13
 RUN du -b /build/imhex.wasm | cut -f1 > imhex.wasm.size
 
-FROM scratch as raw
+FROM scratch AS raw
 COPY --from=build [             \
     # ImHex                     \
     "/build/imhex.wasm",        \
diff --git a/main/gui/CMakeLists.txt b/main/gui/CMakeLists.txt
index d2f8a835f..05b71c287 100644
--- a/main/gui/CMakeLists.txt
+++ b/main/gui/CMakeLists.txt
@@ -44,7 +44,7 @@ if (EMSCRIPTEN)
     target_link_options(main PRIVATE -sEXPORTED_RUNTIME_METHODS=ccall)
     target_link_options(main PRIVATE -sFETCH)
     target_link_options(main PRIVATE -sWASM_BIGINT)
-    target_link_options(main PRIVATE -O1)
+    target_link_options(main PRIVATE -O2)
     target_link_options(main PRIVATE -sLEGACY_GL_EMULATION)
     target_link_options(main PRIVATE -fsanitize=null)
     target_link_options(main PRIVATE -fsanitize-minimal-runtime)