diff --git a/.github/scripts/install_deps.sh b/.github/scripts/install_deps.sh
index fa5e74b11..e864e45fa 100755
--- a/.github/scripts/install_deps.sh
+++ b/.github/scripts/install_deps.sh
@@ -2,10 +2,32 @@
 # This script requires `sh` instead of `bash` because the latter is not always installed on FreeBSD.
 set -eu
 
-case "${1%%-*}" in
+case $# in
+	1) OS="$1"; TOOLSET=    ;;
+	2) OS="$1"; TOOLSET="$2";;
+	*) echo >&2 "Usage: $0 <os> [toolset]" && exit 1;;
+esac
+
+case "${OS%%-*}" in
 	ubuntu|debian)
-		sudo apt-get -qq update
-		sudo apt-get install -yq bison libpng-dev pkgconf
+		pkgs=bison
+		case "$TOOLSET" in
+			mingw32)
+				pkgs="$pkgs libz-mingw-w64-dev g++-mingw-w64-i686-win32"
+				TOOLSET=
+			;;
+			mingw64)
+				pkgs="$pkgs libz-mingw-w64-dev g++-mingw-w64-x86-64-win32"
+				TOOLSET=
+			;;
+			'' | lcov)
+				pkgs="$pkgs libpng-dev pkgconf $TOOLSET"
+				TOOLSET=
+			;;
+		esac
+		sudo apt-get update -qq
+		# shellcheck disable=SC2086 # (This word splitting is intentional.)
+		sudo apt-get install -yq $pkgs
 		;;
 	macos)
 		# macOS bundles GNU Make 3.81, which doesn't support synced output.
@@ -32,6 +54,11 @@ case "${1%%-*}" in
 		;;
 esac
 
+if [ -n "$TOOLSET" ]; then
+	printf >&2 'Unknown toolset `%s` for OS `%s`\n' "$TOOLSET" "$OS"
+	exit 1
+fi
+
 # Print some system info, for easier debugging.
 # https://docs.github.com/en/actions/reference/workflows-and-actions/workflow-commands#grouping-log-lines
 
diff --git a/.github/scripts/mingw-w64-libpng-dev.sh b/.github/scripts/mingw-w64-libpng-dev.sh
deleted file mode 100755
index 77842a75e..000000000
--- a/.github/scripts/mingw-w64-libpng-dev.sh
+++ /dev/null
@@ -1,29 +0,0 @@
-#!/bin/bash
-set -euo pipefail
-
-pngver=1.6.56
-arch="$1"
-
-## Grab sources and check them
-
-wget http://downloads.sourceforge.net/project/libpng/libpng16/$pngver/libpng-$pngver.tar.xz
-echo f7d8bf1601b7804f583a254ab343a6549ca6cf27d255c302c47af2d9d36a6f18 \*libpng-$pngver.tar.xz | \
-	sha256sum -c -
-
-## Extract sources and patch them
-
-tar -xf libpng-$pngver.tar.xz
-
-## Start building!
-
-mkdir -p build
-cd build
-../libpng-$pngver/configure \
-	--host="$arch" --target="$arch" \
-	--prefix="/usr/$arch" \
-	--enable-shared --disable-static \
-	CPPFLAGS="-D_FORTIFY_SOURCE=2" \
-	CFLAGS="-O2 -pipe -fno-plt -fno-exceptions --param=ssp-buffer-size=4" \
-	LDFLAGS="-Wl,-O1,--sort-common,--as-needed -fstack-protector"
-make -kj
-sudo make install
diff --git a/.github/workflows/coverage.yml b/.github/workflows/coverage.yml
index ed08bf691..8451017ba 100644
--- a/.github/workflows/coverage.yml
+++ b/.github/workflows/coverage.yml
@@ -11,16 +11,13 @@ env:
 
 jobs:
   coverage:
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-latest
     steps:
       - name: Checkout repo
         uses: actions/checkout@v6
       - name: Install deps
         run: |
-          ./.github/scripts/install_deps.sh ubuntu
-      - name: Install LCOV
-        run: |
-          sudo apt-get install lcov
+          .github/scripts/install_deps.sh ubuntu-latest lcov
       - name: Install test dependency dependencies
         run: |
           test/fetch-test-deps.sh --get-deps ubuntu
diff --git a/.github/workflows/testing.yml b/.github/workflows/testing.yml
index 3712812ec..fa1db43e8 100644
--- a/.github/workflows/testing.yml
+++ b/.github/workflows/testing.yml
@@ -49,7 +49,7 @@ jobs:
         uses: actions/checkout@v6
       - name: Install deps
         run: |
-          ./.github/scripts/install_deps.sh ${{ matrix.os }}
+          .github/scripts/install_deps.sh ${{ matrix.os }}
       - name: Build & install using Make
         if: matrix.buildsys == 'make'
         run: |
@@ -113,7 +113,7 @@ jobs:
         uses: actions/checkout@v6
       - name: Install deps
         run: |
-          ./.github/scripts/install_deps.sh macos
+          .github/scripts/install_deps.sh macos
       - name: Cache library deps
         uses: actions/cache@v5
         with:
@@ -222,45 +222,29 @@ jobs:
     strategy:
       matrix:
         bits: [32, 64]
-        include:
-          - bits: 32
-            arch: i686
-            triplet: i686-w64-mingw32
-          - bits: 64
-            arch: x86-64
-            triplet: x86_64-w64-mingw32
       fail-fast: false
-    runs-on: ubuntu-22.04
-    env:
-      DIST_DIR: win${{ matrix.bits }}
+    runs-on: ubuntu-latest
     steps:
       - name: Checkout repo
         uses: actions/checkout@v6
       - name: Install deps
         run: |
-          ./.github/scripts/install_deps.sh ubuntu
-      - name: Install MinGW
-        run: | # dpkg-dev is apparently required for pkg-config for cross-building
-          sudo apt-get install g++-mingw-w64-${{ matrix.arch }}-win32 mingw-w64-tools libz-mingw-w64-dev dpkg-dev
-      - name: Install libpng dev headers for MinGW
-        run: |
-          ./.github/scripts/mingw-w64-libpng-dev.sh ${{ matrix.triplet }}
+          .github/scripts/install_deps.sh ubuntu mingw${{ matrix.bits }}
       - name: Cross-build Windows binaries
-        run: |
-          make mingw${{ matrix.bits }} -kj Q=
+        run: | # MinGW does not support `--preset develop` sanitizers ASan or UBSan.
+          dll_search_dir=$(printf '%s\n' /usr/lib/gcc/*-w64-mingw32/*-win32 | tee -a /dev/stderr)
+          cmake -B build --preset develop -DSANITIZERS=OFF --toolchain cmake/toolchain-mingw${{ matrix.bits }}.cmake \
+            -DFETCHCONTENT_BASE_DIR="${{ env.DEPS_ROOT_DIR }}" -DDLL_SEARCH_DIRS="$dll_search_dir"
+          cmake --build build
       - name: Package binaries
-        run: | # DLL dependencies can be figured out using e.g. Dependency Walker or objdump -p
-          mkdir bins
-          mv -v rgb{asm,link,fix,gfx}.exe bins/
-          cp -v /usr/${{ matrix.triplet }}/lib/zlib1.dll bins
-          cp -v /usr/${{ matrix.triplet }}/bin/libpng16-16.dll bins
-          cp -v /usr/lib/gcc/${{ matrix.triplet }}/10-win32/lib{ssp-0,stdc++-6}.dll bins
-          [ "${{ matrix.bits }}" -ne 32 ] || cp -v /usr/lib/gcc/${{ matrix.triplet }}/10-win32/libgcc_s_dw2-1.dll bins
+        run: |
+          cmake --install build --prefix . --verbose --component binaries
+          cmake --install build --prefix . --verbose --component shared-libs
       - name: Upload Windows binaries
         uses: actions/upload-artifact@v7
         with:
           name: rgbds-canary-mingw-win${{ matrix.bits }}
-          path: bins
+          path: bin
           if-no-files-found: error
       - name: Upload Windows test binaries
         uses: actions/upload-artifact@v7
diff --git a/.gitignore b/.gitignore
index e78169b0c..be15d21b7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -14,6 +14,6 @@ CMakeCache.txt
 CMakeFiles/
 cmake_install.cmake
 CMakeUserPresets.json
-build/
+build*/
 *.dSYM/
 callgrind.out.*
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 320a76c51..c46928da9 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -33,31 +33,18 @@ endif()
 
 include(CTest) # Note: CTest only functions properly if included from the top-level CMakeLists.
 include(GNUInstallDirs)
+include(CMakeDependentOption)
 
-## Compiler switches.
+## Compiler switches that should apply to our deps too.
 
-include(CMakeDependentOption)
 option(SANITIZERS "Build with sanitizers enabled" OFF)
 cmake_dependent_option(MORE_WARNINGS "Turn on more warnings" OFF "NOT MSVC" OFF)
 
-if(MSVC)
-  add_compile_options(
-    /wd5030 # Warning C5030 is about unknown attributes (`[[gnu::ATTR]]`), none of ours being load-bearing.
-    /wd4996 # Warning C4996 is about using POSIX names, which we want to do for portability.
-    /Zc:preprocessor # Opt into the C++20-conformant preprocessor.
-  )
-  add_definitions(/D_CRT_SECURE_NO_WARNINGS)
-
-  if(SANITIZERS)
+if(SANITIZERS)
+  if(MSVC)
     message(STATUS "ASan enabled")
     add_compile_options(/fsanitize=address) # Note that this shouldn't be passed to the linker.
-  endif()
-else()
-  add_compile_options(-Wall -pedantic -fno-exceptions $<$<COMPILE_LANGUAGE:CXX>:-fno-rtti> -Wno-unknown-warning-option
-    # C++20 allows macros to take zero variadic arguments.
-    # Some versions of Clang don't recognize this, and treat them as a GNU extension.
-    -Wno-gnu-zero-variadic-macro-arguments)
-  if(SANITIZERS)
+  else() # We assume a GNU-like compiler.
     message(STATUS "ASan and UBSan enabled")
     set(SAN_FLAGS -fsanitize=address -fsanitize=undefined
                   -fsanitize=float-divide-by-zero)
@@ -69,18 +56,6 @@ else()
     # be able to override these easily so we put them first.
     string(PREPEND CMAKE_CXX_FLAGS_DEBUG "-Og -fno-omit-frame-pointer -fno-optimize-sibling-calls ")
   endif()
-
-  if(MORE_WARNINGS)
-    add_compile_options(-Werror -Wextra
-                        -Walloc-zero -Wcast-align -Wcast-qual -Wduplicated-branches -Wduplicated-cond
-                        -Wfloat-equal -Wlogical-op -Wnull-dereference -Wold-style-cast -Wshift-overflow=2
-                        -Wstringop-overflow=4 -Wtrampolines -Wundef -Wuninitialized -Wunused -Wshadow
-                        -Wformat=2 -Wformat-overflow=2 -Wformat-truncation=1
-                        -Wno-format-nonliteral -Wno-strict-overflow
-                        -Wno-unused-but-set-variable # bison's `yynerrs_` is incremented but unused
-                        -Wno-type-limits -Wno-tautological-constant-out-of-range-compare
-                        -Wvla) # MSVC does not support VLAs
-  endif()
 endif()
 
 message(CHECK_START "Checking if LTO is supported")
@@ -164,6 +139,40 @@ include_directories("include")
 set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED True)
 
+if(MSVC)
+  add_compile_options(
+    /wd5030 # Warning C5030 is about unknown attributes (`[[gnu::ATTR]]`), none of ours being load-bearing.
+    /wd4996 # Warning C4996 is about using POSIX names, which we want to do for portability.
+    /Zc:preprocessor # Opt into the C++20-conformant preprocessor.
+  )
+  add_definitions(/D_CRT_SECURE_NO_WARNINGS)
+else()
+  add_compile_options(-Wall -pedantic -fno-exceptions -fno-rtti -Wno-unknown-warning-option
+                      # C++20 allows macros to take zero variadic arguments.
+                      # Some versions of Clang don't recognize this, and treat them as a GNU extension.
+                      -Wno-gnu-zero-variadic-macro-arguments)
+
+  if(MORE_WARNINGS)
+    add_compile_options(-Wextra
+                        -Walloc-zero -Wcast-align -Wcast-qual -Wduplicated-branches -Wduplicated-cond
+                        -Wfloat-equal -Wlogical-op -Wnull-dereference -Wold-style-cast -Wshift-overflow=2
+                        -Wstringop-overflow=4 -Wtrampolines -Wundef -Wuninitialized -Wunused -Wshadow
+                        -Wformat=2 -Wformat-overflow=2 -Wformat-truncation=1
+                        -Wno-format-nonliteral -Wno-strict-overflow
+                        -Wno-unused-but-set-variable # bison's `yynerrs_` is incremented but unused
+                        -Wno-type-limits -Wno-tautological-constant-out-of-range-compare
+                        -Wvla) # MSVC does not support VLAs
+  endif()
+
+  if(MINGW)
+    # MinGW warns about format specifiers like `%z` and `%j`, which are missing on Windows XP and earlier.
+    # We rely on runtimes more modern than that, so we can ignore those warnings.
+    # If this is a problem for you: use Microsoft's equivalents, or define `__USE_MINGW_ANSI_STDIO=1`.
+    # https://sourceforge.net/p/mingw-w64/wiki2/gnu%20printf/
+    add_compile_options(-Wno-error=format -Wno-error=format-extra-args)
+  endif()
+endif()
+
 add_subdirectory(src)
 if(BUILD_TESTING) # This option is defined implicitly by `include(CTest)`.
   add_subdirectory(test)
@@ -202,4 +211,5 @@ set(CPACK_STRIP_FILES ON) # Only applies to binary packages, not sources.
 set(CPACK_VERBATIM_VARIABLES ON)
 set(CPACK_THREADS 0) # Use all available CPU cores.
 set(CPACK_INCLUDE_TOPLEVEL_DIRECTORY OFF)
+
 include(CPack)
diff --git a/CMakePresets.json b/CMakePresets.json
index 255c4db74..74b4d18fb 100644
--- a/CMakePresets.json
+++ b/CMakePresets.json
@@ -7,6 +7,8 @@
 			"cacheVariables": {
 				"CMAKE_BUILD_TYPE": "Debug",
 				"CMAKE_EXPORT_COMPILE_COMMANDS": true,
+				"CMAKE_COMPILE_WARNING_AS_ERROR": true,
+				"CMAKE_LINK_WARNING_AS_ERROR": true,
 				"MORE_WARNINGS": true,
 				"SANITIZERS": true
 			},
diff --git a/Makefile b/Makefile
index 3908ee032..b8235290d 100644
--- a/Makefile
+++ b/Makefile
@@ -3,7 +3,7 @@
 .SUFFIXES:
 .SUFFIXES: .cpp .y .o
 
-.PHONY: all clean install checkdiff develop debug profile coverage format tidy iwyu mingw32 mingw64 wine-shim dist
+.PHONY: all clean install checkdiff develop debug profile coverage format tidy iwyu wine-shim dist
 
 # User-defined variables
 
@@ -256,22 +256,6 @@ iwyu:
 		CXX="include-what-you-use" \
 		REALCXXFLAGS="-std=c++20 -I include"
 
-# Targets for the project maintainer to easily create Windows exes.
-# This is not for Windows users!
-# If you're building on Windows with Cygwin or MinGW, just follow the Unix
-# install instructions instead.
-
-mingw32:
-	$Q${MAKE} all test/gfx/randtilegen test/gfx/rgbgfx_test \
-		CXX=i686-w64-mingw32-g++ \
-		CXXFLAGS="-O3 -flto -DNDEBUG -static-libgcc -static-libstdc++" \
-		PKG_CONFIG="PKG_CONFIG_SYSROOT_DIR=/usr/i686-w64-mingw32 pkg-config"
-
-mingw64:
-	$Q${MAKE} all test/gfx/randtilegen test/gfx/rgbgfx_test \
-		CXX=x86_64-w64-mingw32-g++ \
-		PKG_CONFIG="PKG_CONFIG_SYSROOT_DIR=/usr/x86_64-w64-mingw32 pkg-config"
-
 wine-shim:
 	$Qecho '#!/usr/bin/env bash' > rgbshim.sh
 	$Qecho 'WINEDEBUG=-all wine $$0.exe "$${@:1}"' >> rgbshim.sh
diff --git a/cmake/toolchain-mingw32.cmake b/cmake/toolchain-mingw32.cmake
new file mode 100644
index 000000000..13f67e58e
--- /dev/null
+++ b/cmake/toolchain-mingw32.cmake
@@ -0,0 +1,22 @@
+# From https://www.mingw-w64.org/build-systems/cmake/
+
+set(CMAKE_SYSTEM_NAME Windows)
+set(CMAKE_SYSTEM_PROCESSOR i686)
+
+# Specify the cross-compiler.
+set(CMAKE_C_COMPILER i686-w64-mingw32-gcc)
+set(CMAKE_CXX_COMPILER i686-w64-mingw32-g++)
+set(CMAKE_RC_COMPILER i686-w64-mingw32-windres)
+
+# Specify the target environment.
+set(CMAKE_FIND_ROOT_PATH /usr/i686-w64-mingw32)
+
+# Search for programs in the build host directories.
+set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
+# Search for libraries and headers in the target directories.
+set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
+
+# CMake determines how to examine dependencies based on the *host* system, leading to
+# a "file unknown error" unless the target platform is explicitly specified.
+set(CMAKE_GET_RUNTIME_DEPENDENCIES_PLATFORM "windows+pe")
diff --git a/cmake/toolchain-mingw64.cmake b/cmake/toolchain-mingw64.cmake
new file mode 100644
index 000000000..76d8a70d1
--- /dev/null
+++ b/cmake/toolchain-mingw64.cmake
@@ -0,0 +1,22 @@
+# From https://www.mingw-w64.org/build-systems/cmake/
+
+set(CMAKE_SYSTEM_NAME Windows)
+set(CMAKE_SYSTEM_PROCESSOR x86_64)
+
+# Specify the cross-compiler.
+set(CMAKE_C_COMPILER x86_64-w64-mingw32-gcc)
+set(CMAKE_CXX_COMPILER x86_64-w64-mingw32-g++)
+set(CMAKE_RC_COMPILER x86_64-w64-mingw32-windres)
+
+# Specify the target environment.
+set(CMAKE_FIND_ROOT_PATH /usr/x86_64-w64-mingw32)
+
+# Search for programs in the build host directories.
+set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
+# Search for libraries and headers in the target directories.
+set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
+
+# CMake determines how to examine dependencies based on the *host* system, leading to
+# a "file unknown error" unless the target platform is explicitly specified.
+set(CMAKE_GET_RUNTIME_DEPENDENCIES_PLATFORM "windows+pe")
diff --git a/src/asm/lexer.cpp b/src/asm/lexer.cpp
index 6739e90ab..8801093dc 100644
--- a/src/asm/lexer.cpp
+++ b/src/asm/lexer.cpp
@@ -358,7 +358,7 @@ void LexerState::setFileAsNextState(std::string const &filePath, bool updateStat
 				fatal("Failed to read file \"%s\": %s", path.c_str(), strerror(errno));
 				// LCOV_EXCL_STOP
 			}
-			content.emplace<ViewedContent>(ptr, size);
+			content.emplace<ViewedContent>(ptr, static_cast<size_t>(size));
 
 			// LCOV_EXCL_START
 			verbosePrint(VERB_INFO, "File \"%s\" is fully read\n", path.c_str());
diff --git a/src/asm/section.cpp b/src/asm/section.cpp
index ffc296094..24dd943d1 100644
--- a/src/asm/section.cpp
+++ b/src/asm/section.cpp
@@ -934,8 +934,14 @@ bool sect_BinaryFile(std::string const &name, uint32_t startPos) {
 	Defer closeFile{[&] { fclose(file); }};
 
 	if (fseek(file, 0, SEEK_END) == 0) {
-		if (startPos > ftell(file)) {
-			error("Specified start position is greater than length of file \"%s\"", name.c_str());
+		if (unsigned long fsize = ftell(file);
+		    startPos > fsize) { // `ftell` cannot fail here, since `fseek` succeeded.
+			error(
+			    "Specified start position (%" PRIu32 ") is greater than length of \"%s\" (%lu)",
+			    startPos,
+			    name.c_str(),
+			    fsize
+			);
 			return false;
 		}
 		// The file is seekable; skip to the specified start position
@@ -989,8 +995,14 @@ bool sect_BinaryFileSlice(std::string const &name, uint32_t startPos, uint32_t l
 	Defer closeFile{[&] { fclose(file); }};
 
 	if (fseek(file, 0, SEEK_END) == 0) {
-		if (long fsize = ftell(file); startPos > fsize) {
-			error("Specified start position is greater than length of file \"%s\"", name.c_str());
+		if (unsigned long fsize = ftell(file);
+		    startPos > fsize) { // `ftell` cannot fail here, since `fseek` succeeded.
+			error(
+			    "Specified start position (%" PRIu32 ") is greater than length of \"%s\" (%lu)",
+			    startPos,
+			    name.c_str(),
+			    fsize
+			);
 			return false;
 		} else if (startPos + length > fsize) {
 			error(
diff --git a/src/link/sdas_obj.cpp b/src/link/sdas_obj.cpp
index 35dd5b25e..134ff7c38 100644
--- a/src/link/sdas_obj.cpp
+++ b/src/link/sdas_obj.cpp
@@ -661,8 +661,8 @@ void sdobj_ReadFile(FileStackNode const &src, FILE *file, std::vector<Symbol> &f
 						patch.rpnExpression[0] = RPN_BANK_SYM;
 						patch.rpnExpression[1] = idx;
 						patch.rpnExpression[2] = idx >> 8;
-						patch.rpnExpression[3] = idx >> 16;
-						patch.rpnExpression[4] = idx >> 24;
+						patch.rpnExpression[3] = 0;
+						patch.rpnExpression[4] = 0;
 					} else if (sym.name.starts_with("l_")) {
 						patch.rpnExpression.resize(1 + sym.name.length() - 2 + 1);
 						patch.rpnExpression[0] = RPN_SIZEOF_SECT;
@@ -684,8 +684,8 @@ void sdobj_ReadFile(FileStackNode const &src, FILE *file, std::vector<Symbol> &f
 						patch.rpnExpression[0] = RPN_SYM;
 						patch.rpnExpression[1] = idx;
 						patch.rpnExpression[2] = idx >> 8;
-						patch.rpnExpression[3] = idx >> 16;
-						patch.rpnExpression[4] = idx >> 24;
+						patch.rpnExpression[3] = 0;
+						patch.rpnExpression[4] = 0;
 					}
 				} else {
 					if (idx >= fileSections.size()) {
diff --git a/test/asm/incbin-start-bad.err b/test/asm/incbin-start-bad.err
index f5e8c5997..b32c937dd 100644
--- a/test/asm/incbin-start-bad.err
+++ b/test/asm/incbin-start-bad.err
@@ -1,5 +1,5 @@
-error: Specified start position is greater than length of file "data.bin"
+error: Specified start position (999) is greater than length of "data.bin" (123)
     at incbin-start-bad.asm(3)
-error: Specified start position is greater than length of file "data.bin"
+error: Specified start position (999) is greater than length of "data.bin" (123)
     at incbin-start-bad.asm(4)
 Assembly aborted with 2 errors
diff --git a/test/gfx/rgbgfx_test.cpp b/test/gfx/rgbgfx_test.cpp
index f1f1a1779..8691d80e3 100644
--- a/test/gfx/rgbgfx_test.cpp
+++ b/test/gfx/rgbgfx_test.cpp
@@ -320,7 +320,7 @@ static char *execProg(char const *name, char * const *argv) {
 		        nullptr,
 		        errnum,
 		        0,
-		        (LPTSTR)&buf,
+		        reinterpret_cast<LPTSTR>(&buf),
 		        0,
 		        nullptr
 		    )
@@ -341,7 +341,8 @@ static char *execProg(char const *name, char * const *argv) {
 
 	STARTUPINFOA startupInfo;
 	GetStartupInfoA(&startupInfo);
-	STARTUPINFOA childStartupInfo = {sizeof(startupInfo)};
+	STARTUPINFOA childStartupInfo = {};
+	childStartupInfo.cb = sizeof(startupInfo);
 
 	PROCESS_INFORMATION child;
 	if (CreateProcessA(