diff --git a/packages/win_installer/fragment_spelling.iss b/packages/win_installer/fragment_spelling.iss
index 331f3eb296..8a5bca5e15 100644
--- a/packages/win_installer/fragment_spelling.iss
+++ b/packages/win_installer/fragment_spelling.iss
@@ -1,5 +1,5 @@
 ; This file declares all installables related to spell checking and thesaurii in Aegisub
 
 [Files]
-Source: {#DEPS_DIR}\dictionaries\en_US.aff; DestDir: {app}\dictionaries; Flags: skipifsourcedoesntexist ignoreversion
-Source: {#DEPS_DIR}\dictionaries\en_US.dic; DestDir: {app}\dictionaries; Flags: skipifsourcedoesntexist ignoreversion
+Source: {#DEPS_DIR}\dictionaries\en_US.aff; DestDir: {app}\dictionaries; Flags: skipifsourcedoesntexist ignoreversion; Components: dictionaries/en_US
+Source: {#DEPS_DIR}\dictionaries\en_US.dic; DestDir: {app}\dictionaries; Flags: skipifsourcedoesntexist ignoreversion; Components: dictionaries/en_US
diff --git a/packages/win_installer/portable/create-portable.ps1 b/packages/win_installer/portable/create-portable.ps1
index 1bb045bed9..0a23ceb223 100644
--- a/packages/win_installer/portable/create-portable.ps1
+++ b/packages/win_installer/portable/create-portable.ps1
@@ -51,6 +51,9 @@ Copy-New-Item $InstallerDir\bin\aegisub.exe  $PortableOutputDir
 
 Write-Output 'Copying - translations'
 Copy-New-Items "$InstallerDir\share\locale\*"  "$PortableOutputDir\locale" -Recurse
+Write-Output 'Copying - dictionaries'
+Copy-New-Item $InstallerDepsDir\dictionaries\en_US.aff  $PortableOutputDir\dictionaries
+Copy-New-Item $InstallerDepsDir\dictionaries\en_US.dic  $PortableOutputDir\dictionaries
 Write-Output 'Copying - codecs'
 Write-Output 'Copying - codecs\Avisynth'
 Copy-New-Item $InstallerDepsDir\AvisynthPlus64\x64\Output\system\DevIL.dll  $PortableOutputDir
diff --git a/tools/osx-bundle.sh b/tools/osx-bundle.sh
index f8d4a682ed..29e0fbfd97 100755
--- a/tools/osx-bundle.sh
+++ b/tools/osx-bundle.sh
@@ -61,7 +61,14 @@ echo "---- Copying dictionaries ----"
 if test -f "${DICT_DIR}"; then
   cp -v "${DICT_DIR}/*" "${PKG_DIR}/Contents/SharedSupport/dictionaries"
 else
-  echo "Specified dictionary directory ${DICT_DIR} not found!"
+  mkdir -p "${BUILD_DIR}/dictionaries"
+  if ! test -f "${BUILD_DIR}/dictionaries/en_US.aff"; then
+      echo "Specified dictionary directory ${DICT_DIR} not found. Downloading dictionaries:"
+      curl -L "https://downloads.sourceforge.net/project/openofficeorg.mirror/contrib/dictionaries/en_US.zip" -o "${BUILD_DIR}/dictionaries/en_US.zip"
+      unzip "${BUILD_DIR}/dictionaries/en_US.zip" -d "${BUILD_DIR}/dictionaries"
+  fi
+  cp -v "${BUILD_DIR}/dictionaries/en_US.aff" "${PKG_DIR}/Contents/SharedSupport/dictionaries"
+  cp -v "${BUILD_DIR}/dictionaries/en_US.dic" "${PKG_DIR}/Contents/SharedSupport/dictionaries"
 fi
 
 echo
diff --git a/tools/win-installer-setup.ps1 b/tools/win-installer-setup.ps1
index ae1457e960..ca46d88863 100644
--- a/tools/win-installer-setup.ps1
+++ b/tools/win-installer-setup.ps1
@@ -81,7 +81,14 @@ if (!(Test-Path VC_redist)) {
 	Invoke-WebRequest https://aka.ms/vs/17/release/VC_redist.x64.exe -OutFile "$redistDir\VC_redist.x64.exe" -UseBasicParsing
 }
 
-# TODO dictionaries
+# dictionaries
+if (!(Test-Path dictionaries)) {
+	New-Item -ItemType Directory dictionaries
+	[Net.ServicePointManager]::SecurityProtocol = "Tls12" 	# Needed since otherwise downloading fails in some places like on the GitHub CI: https://stackoverflow.com/a/66614041/4730656
+	Invoke-WebRequest https://downloads.sourceforge.net/project/openofficeorg.mirror/contrib/dictionaries/en_US.zip -UserAgent "Wget" -OutFile en_US.zip -UseBasicParsing
+	Expand-Archive -LiteralPath en_US.zip -DestinationPath dictionaries
+	Remove-Item en_US.zip
+}
 
 # localization
 Set-Location $BuildRoot