diff --git a/launcher/modplatform/flame/FlameModIndex.cpp b/launcher/modplatform/flame/FlameModIndex.cpp
index 345883c17..70d07c201 100644
--- a/launcher/modplatform/flame/FlameModIndex.cpp
+++ b/launcher/modplatform/flame/FlameModIndex.cpp
@@ -138,6 +138,9 @@ auto FlameMod::loadIndexedPackVersion(QJsonObject& obj, bool load_changelog) ->
     file.version = Json::requireString(obj, "displayName");
     file.downloadUrl = Json::ensureString(obj, "downloadUrl");
     file.fileName = Json::requireString(obj, "fileName");
+#ifdef Q_OS_WIN
+    file.fileName = FS::RemoveInvalidPathChars(file.fileName);
+#endif
 
     ModPlatform::IndexedVersionType::VersionType ver_type;
     switch (Json::requireInteger(obj, "releaseType")) {
diff --git a/launcher/modplatform/modrinth/ModrinthPackIndex.cpp b/launcher/modplatform/modrinth/ModrinthPackIndex.cpp
index c1c30ab5f..561976dc3 100644
--- a/launcher/modplatform/modrinth/ModrinthPackIndex.cpp
+++ b/launcher/modplatform/modrinth/ModrinthPackIndex.cpp
@@ -226,6 +226,9 @@ auto Modrinth::loadIndexedPackVersion(QJsonObject& obj, QString preferred_hash_t
     if (parent.contains("url")) {
         file.downloadUrl = Json::requireString(parent, "url");
         file.fileName = Json::requireString(parent, "filename");
+#ifdef Q_OS_WIN
+        file.fileName = FS::RemoveInvalidPathChars(file.fileName);
+#endif
         file.is_preferred = Json::requireBoolean(parent, "primary") || (files.count() == 1);
         auto hash_list = Json::requireObject(parent, "hashes");