diff --git a/windows/src/desktop/kmshell/install/Keyman.Configuration.UI.KeymanProtocolHandler.pas b/windows/src/desktop/kmshell/install/Keyman.Configuration.UI.KeymanProtocolHandler.pas
index 8b78fa7601..feadd80945 100644
--- a/windows/src/desktop/kmshell/install/Keyman.Configuration.UI.KeymanProtocolHandler.pas
+++ b/windows/src/desktop/kmshell/install/Keyman.Configuration.UI.KeymanProtocolHandler.pas
@@ -39,6 +39,7 @@ uses
   UfrmInstallKeyboard,
   Upload_Settings,
   utildir,
+  IdURI,
   utilfiletypes;
 
 { TKeymanProtocolHandler }
@@ -84,7 +85,7 @@ begin
   // TODO: refactor into separate unit together with code from UfrmInstallKeyboardFromWeb
   FTempDir := IncludeTrailingPathDelimiter(CreateTempPath);  // I1679
   try
-    FDownloadFilename := FTempDir + PackageID + Ext_PackageFile;
+    FDownloadFilename := FTempDir + TIdURI.URLDecode(PackageID) + Ext_PackageFile;
     FDownloadURL := KeymanCom_Protocol_Server + URLPath_PackageDownload(PackageID, BCP47, False);
 
     frmDownloadProgress := TfrmDownloadProgress.Create(nil);
diff --git a/windows/src/desktop/kmshell/install/UfrmInstallKeyboardFromWeb.pas b/windows/src/desktop/kmshell/install/UfrmInstallKeyboardFromWeb.pas
index 31e6eafb67..14921a8006 100644
--- a/windows/src/desktop/kmshell/install/UfrmInstallKeyboardFromWeb.pas
+++ b/windows/src/desktop/kmshell/install/UfrmInstallKeyboardFromWeb.pas
@@ -91,6 +91,7 @@ uses
   Upload_Settings,
   utilfiletypes,
   utildir,
+  IdURI,
   utilexecute,
   VersionInfo;
 
@@ -215,7 +216,7 @@ var
 begin
   FTempDir := IncludeTrailingPathDelimiter(CreateTempPath);  // I1679
   try
-    FDownloadFilename := FTempDir + PackageID + Ext_PackageFile;
+    FDownloadFilename := FTempDir + TIdURI.URLDecode(PackageID) + Ext_PackageFile;
     FDownloadURL := KeymanCom_Protocol_Server + URLPath_PackageDownload(PackageID, BCP47, False);
 
     frmDownloadProgress := TfrmDownloadProgress.Create(Self);