diff --git a/.gitignore b/.gitignore
index 00e20db8da..b753d1cf66 100644
--- a/.gitignore
+++ b/.gitignore
@@ -40,6 +40,7 @@ build
 #ignore external deps
 external_deps/*
 !external_deps/build.sh
+!external_deps/sdk-build.sh
 !external_deps/cygtar.py
 !external_deps/*.patch
 
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 65ff1a430b..4c360308eb 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -157,6 +157,12 @@ set(NACL_VM_INHERITED_OPTIONS "${DEFAULT_NACL_VM_INHERITED_OPTIONS}" CACHE STRIN
     "Semicolon-separated list of options for which NaCl game VMs should use the same value as the other binaries")
 mark_as_advanced(NACL_VM_INHERITED_OPTIONS)
 
+# Warning: changing SAIGOSDK_ROOT/SAIGOSDK_VERSION after subprojects have been configured WILL
+# change the compiler, but it is a bad idea since flag tests and such (not to mention the actual
+# compiled artifacts) will be out of date.
+set(SAIGOSDK_ROOT "" CACHE PATH "Override Saigo NaCl SDK path")
+mark_as_advanced(SAIGOSDK_ROOT)
+
 ################################################################################
 # Directories
 ################################################################################
@@ -189,8 +195,9 @@ else()
     set(FULL_OUTPUT_DIR ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR})
 endif()
 
-# Dependencies version, this must match the number in external_deps/build.sh
-set(DEPS_VERSION 11)
+# Dependencies versions
+set(DEPS_VERSION 11) # This must match the number in external_deps/build.sh
+set(SAIGOSDK_VERSION 20260925) # This must match the number in external_deps/sdk-build.sh
 
 option(USE_EXTERNAL_DEPS "Download or reuse dependencies from EXTERNAL_DEPS_DIR (mandatory for building and running NaCl .nexe binaries)." ON)
 
@@ -442,6 +449,11 @@ if (DEPS_DIR)
         endif()
     endif()
 
+    if (BUILD_GAME_NACL AND USE_NACL_SAIGO AND NOT SAIGOSDK_ROOT)
+        include(DaemonDependenciesDownload)
+        download_saigosdk()
+    endif()
+
     if (USE_EXTERNAL_DEPS_LIBS)
         # Add to paths
         set(CMAKE_FIND_ROOT_PATH ${DEPS_DIR} ${CMAKE_FIND_ROOT_PATH})
@@ -487,10 +499,10 @@ elseif (YOKAI_TARGET_SYSTEM_NACL)
     if (NOT NACL_MINIDUMP
     # NACL_TARGET is specific to Saigo, PNaCl target is le32 and doesn't set NACL_TARGET.
     AND "${NACL_TARGET}" STREQUAL "i686"
-    # x86_64-nacl/lib32 is specific to Google build, other builds may provide i686-nacl/lib instead.
-    AND EXISTS "${DEPS_DIR}/saigo_newlib/x86_64-nacl/lib32")
-        set(NACL_EXCEPTION "${DEPS_DIR}/saigo_newlib/x86_64-nacl/lib32/libnacl_exception.a")
-        set(NACL_MINIDUMP "${DEPS_DIR}/saigo_newlib/x86_64-nacl/lib32/libminidump_generator.a")
+    # Other builds may provide i686-nacl/lib instead.
+    AND EXISTS "${SAIGOSDK_ROOT}/x86_64-nacl/lib32")
+        set(NACL_EXCEPTION "${SAIGOSDK_ROOT}/x86_64-nacl/lib32/libnacl_exception.a")
+        set(NACL_MINIDUMP "${SAIGOSDK_ROOT}/x86_64-nacl/lib32/libminidump_generator.a")
     endif()
 
     set(LIBS_BASE ${LIBS_BASE} ${NACL_MINIDUMP} ${NACL_EXCEPTION})
diff --git a/cmake/DaemonDependenciesDownload.cmake b/cmake/DaemonDependenciesDownload.cmake
new file mode 100644
index 0000000000..93f6aa45b9
--- /dev/null
+++ b/cmake/DaemonDependenciesDownload.cmake
@@ -0,0 +1,70 @@
+# Daemon BSD Source Code
+# Copyright (c) 2013-2026, Daemon Developers
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#  * Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+#  * Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#  * Neither the name of the Daemon developers nor the
+#    names of its contributors may be used to endorse or promote products
+#    derived from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL DAEMON DEVELOPERS BE LIABLE FOR ANY
+# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+# TODO: Move other deps downloading code in here.
+
+set(SAIGOSDK_BASENAME saigosdk-${DEPS_SYSTEM}-${DEPS_ARCH}_${SAIGOSDK_VERSION})
+set(SAIGOSDK_ROOT ${EXTERNAL_DEPS_DIR}/${SAIGOSDK_BASENAME})
+set(SAIGOSDK_ROOT "${SAIGOSDK_ROOT}" PARENT_SCOPE)
+
+# As an alternative to downloading, external_deps/sdk-build.sh can be used, to build the host-mode
+# dependencies and install them in the expected path.
+function(download_saigosdk)
+    if (NOT EXISTS ${SAIGOSDK_ROOT})
+        set(DEPS_FILENAME "${SAIGOSDK_BASENAME}.tar.xz")
+        set(REMOTE "https://github.com/DaemonEngine/saigo-nacl-sdk/releases/download/v${SAIGOSDK_VERSION}/${DEPS_FILENAME}")
+        message(STATUS "Downloading NaCl SDK from '${REMOTE}'")
+
+        file(DOWNLOAD "${REMOTE}" "${OBJ_DIR}/${DEPS_FILENAME}"
+            SHOW_PROGRESS
+            STATUS DOWNLOAD_RESULT
+            LOG DOWNLOAD_LOG
+        )
+
+        list(GET DOWNLOAD_RESULT 0 DOWNLOAD_STATUS)
+        list(GET DOWNLOAD_RESULT 1 DOWNLOAD_STRING)
+
+        if (NOT DOWNLOAD_STATUS EQUAL 0)
+            message(FATAL_ERROR "Failed to download '${REMOTE}': This may be a network error, or your system may be an unsupported host platform.
+                Status code: ${DOWNLOAD_STATUS}
+                Error string: ${DOWNLOAD_STRING}
+                Download log: ${DOWNLOAD_LOG}"
+            )
+        endif()
+
+        message(STATUS "SDK download completed successfully")
+
+        # Extract the downloaded archive
+        execute_process(
+            COMMAND ${CMAKE_COMMAND} -E tar xJf ${OBJ_DIR}/${DEPS_FILENAME}
+            WORKING_DIRECTORY ${EXTERNAL_DEPS_DIR}
+            RESULT_VARIABLE EXTRACT_RESULT
+        )
+        if (NOT EXTRACT_RESULT EQUAL 0)
+            message(FATAL_ERROR "Could not extract ${DEPS_FILENAME}")
+        endif()
+    endif()
+endfunction()
diff --git a/cmake/DaemonGame.cmake b/cmake/DaemonGame.cmake
index f6adde3c7c..81dc9348cb 100644
--- a/cmake/DaemonGame.cmake
+++ b/cmake/DaemonGame.cmake
@@ -204,6 +204,9 @@ function(GAMEMODULE)
 
 		if (BUILD_GAME_NACL)
 			if (USE_NACL_SAIGO)
+				if (NOT IS_DIRECTORY "${SAIGOSDK_ROOT}")
+					message(FATAL_ERROR "SAIGOSDK_ROOT configured as '${SAIGOSDK_ROOT}' which is not an existing directory")
+				endif()
 				add_custom_target(nacl-vms ALL)
 				unset(NACL_VMS_PROJECTS)
 
@@ -224,6 +227,7 @@ function(GAMEMODULE)
 
 					gameSubProject(
 						-DCMAKE_TOOLCHAIN_FILE=${Daemon_SOURCE_DIR}/cmake/toolchain-saigo.cmake
+						-DSAIGOSDK_ROOT=${SAIGOSDK_ROOT}
 						-DBUILD_GAME_NACL=ON
 						-DBUILD_GAME_NATIVE_DLL=OFF
 						-DBUILD_GAME_NATIVE_EXE=OFF
diff --git a/cmake/toolchain-saigo.cmake b/cmake/toolchain-saigo.cmake
index 75374527b3..92a576c7d0 100644
--- a/cmake/toolchain-saigo.cmake
+++ b/cmake/toolchain-saigo.cmake
@@ -1,4 +1,4 @@
-set(PLATFORM_PREFIX "${DEPS_DIR}/saigo_newlib/bin")
+set(PLATFORM_PREFIX "${SAIGOSDK_ROOT}/bin")
 set(PLATFORM_TRIPLET "${SAIGO_ARCH}-nacl")
 set(PLATFORM_EXE_SUFFIX ".nexe")
 
diff --git a/external_deps/sdk-build.sh b/external_deps/sdk-build.sh
new file mode 100755
index 0000000000..e90e0ace1f
--- /dev/null
+++ b/external_deps/sdk-build.sh
@@ -0,0 +1,88 @@
+#!/usr/bin/env bash
+
+# Exit on undefined variable and error.
+set -u -e -o pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd)"
+WORK_DIR="${PWD}"
+DOWNLOAD_DIR="${WORK_DIR}/download_cache"
+
+# This should match the SAIGOSDK_VERSION in CMakeLists.txt.
+# This is mostly to ensure the path the files end up at if you build deps yourself
+# are the same as the ones when extracting from the downloaded packages.
+SAIGOSDK_VERSION=20261013
+# Can be a tag like v${SAIGOSDK_VERSION}, or a full commit hash
+SAIGOSDK_REF="v${SAIGOSDK_VERSION}"
+
+REPO_BASENAME=saigo-nacl-sdk
+REPO_URL="https://github.com/DaemonEngine/${REPO_BASENAME}"
+ARCHIVE_PATH="${DOWNLOAD_DIR}/saigosdk-${SAIGOSDK_REF}.tar.gz"
+
+usage() {
+    echo "Usage: $0 <os>-<arch> (build | install | package | wipe)..."
+    echo "<os>-<arch> should normally be your current native platform."
+    echo "For a list of supported platforms see ${REPO_URL}/tree/master/tools/release/conf"
+    echo "Actions:"
+    echo "  build - build all tools and libraries in the SDK"
+    echo "  install - install final build products to ${WORK_DIR}/saigosdk-<os>-<arch>_${SAIGOSDK_VERSION}/"
+    echo "  wipe - delete build products (except download cache) AND install directory"
+    echo "If you want to build only a subset of packages, prefer using the"
+    echo "${REPO_URL} CMake build directly."
+    echo "Some global configuration options are available via environment"
+    echo "variables; see ${REPO_URL}/tree/master/tools/release/build"
+}
+
+download() {
+    test -f "${ARCHIVE_PATH}" && return
+    mkdir -p "${DOWNLOAD_DIR}"
+    curl --fail -L "${DOWNLOAD_URL}" -o "${ARCHIVE_PATH}"
+}
+
+if [ "$#" -lt 2 ]
+then
+    usage
+    exit 1
+fi
+
+PLATFORM="$1"
+shift
+
+if grep -q -E '^[0-9a-f]{40}$' <<< "${SAIGOSDK_REF}"
+then
+    DOWNLOAD_URL="https://github.com/DaemonEngine/saigo-nacl-sdk/archive/${SAIGOSDK_REF}.tar.gz"
+    TARBALL_OUTER_DIR="${REPO_BASENAME}-${SAIGOSDK_REF}"
+elif grep -q -E '^v[0-9]' <<< "${SAIGOSDK_REF}"
+then
+    # The 'v' from the tag name is mysteriously removed???
+    TARBALL_OUTER_DIR="${REPO_BASENAME}-${SAIGOSDK_REF:1}"
+    DOWNLOAD_URL="https://github.com/DaemonEngine/saigo-nacl-sdk/archive/refs/tags/${SAIGOSDK_REF}.tar.gz"
+fi
+
+INSTALL_DIR="${WORK_DIR}/saigosdk-${PLATFORM}_${SAIGOSDK_VERSION}"
+BUILD_DIR="${WORK_DIR}/build-saigosdk_${SAIGOSDK_VERSION}"
+REPO_DIR="${BUILD_DIR}/${TARBALL_OUTER_DIR}"
+
+for target in "$@"
+do
+    case "${target}" in
+    build)
+        download
+        mkdir -p "${BUILD_DIR}"
+        tar xzf "${ARCHIVE_PATH}" -C "${BUILD_DIR}"
+        (
+            cd "${REPO_DIR}"
+            tools/release/build "${PLATFORM}"
+        )
+        ;;
+    install)
+        cp -R "${REPO_DIR}/build/${PLATFORM}/install/." "${INSTALL_DIR}/"
+        ;;
+    wipe)
+        rm -rf "${BUILD_DIR}" "${INSTALL_DIR}"
+        ;;
+    *)
+        usage
+        exit 1
+        ;;
+    esac
+done