diff --git a/dll/steam_remote_storage.h b/dll/steam_remote_storage.h
index 5aa6742..d393c94 100644
--- a/dll/steam_remote_storage.h
+++ b/dll/steam_remote_storage.h
@@ -83,7 +83,7 @@ Steam_Remote_Storage(class Settings *settings, Local_Storage *local_storage, cla
 bool	FileWrite( const char *pchFile, const void *pvData, int32 cubData )
 {
     PRINT_DEBUG("Steam_Remote_Storage::FileWrite %s %u\n", pchFile, cubData);
-    if (!pchFile || cubData <= 0 || cubData > k_unMaxCloudFileChunkSize) {
+    if (!pchFile || cubData <= 0 || cubData > k_unMaxCloudFileChunkSize || !pvData) {
         return false;
     }
 
@@ -96,6 +96,7 @@ bool	FileWrite( const char *pchFile, const void *pvData, int32 cubData )
 int32	FileRead( const char *pchFile, void *pvData, int32 cubDataToRead )
 {
     PRINT_DEBUG("Steam_Remote_Storage::FileRead %s %i\n", pchFile, cubDataToRead);
+    if (!pchFile || !pvData || !cubDataToRead) return 0;
     std::lock_guard<std::recursive_mutex> lock(global_mutex);
     int read_data = local_storage->get_data(Local_Storage::remote_storage_folder, pchFile, (char* )pvData, cubDataToRead);
     if (read_data < 0) read_data = 0;
@@ -107,7 +108,7 @@ STEAM_CALL_RESULT( RemoteStorageFileWriteAsyncComplete_t )
 SteamAPICall_t FileWriteAsync( const char *pchFile, const void *pvData, uint32 cubData )
 {
     PRINT_DEBUG("Steam_Remote_Storage::FileWriteAsync\n");
-    if (!pchFile || cubData > k_unMaxCloudFileChunkSize || cubData == 0) {
+    if (!pchFile || cubData > k_unMaxCloudFileChunkSize || cubData == 0 || !pvData) {
         return k_uAPICallInvalid;
     }
 
@@ -124,6 +125,7 @@ STEAM_CALL_RESULT( RemoteStorageFileReadAsyncComplete_t )
 SteamAPICall_t FileReadAsync( const char *pchFile, uint32 nOffset, uint32 cubToRead )
 {
     PRINT_DEBUG("Steam_Remote_Storage::FileReadAsync\n");
+    if (!pchFile) return k_uAPICallInvalid;
     std::lock_guard<std::recursive_mutex> lock(global_mutex);
 
     unsigned int size = local_storage->file_size(Local_Storage::remote_storage_folder, pchFile);
@@ -151,6 +153,7 @@ SteamAPICall_t FileReadAsync( const char *pchFile, uint32 nOffset, uint32 cubToR
 bool	FileReadAsyncComplete( SteamAPICall_t hReadCall, void *pvBuffer, uint32 cubToRead )
 {
     PRINT_DEBUG("Steam_Remote_Storage::FileReadAsyncComplete\n");
+    if (!pvBuffer) return false;
     std::lock_guard<std::recursive_mutex> lock(global_mutex);
 
     auto a_read = std::find_if(async_reads.begin(), async_reads.end(), [&hReadCall](Async_Read const& item) { return item.api_call == hReadCall; });
@@ -190,6 +193,7 @@ STEAM_CALL_RESULT( RemoteStorageFileShareResult_t )
 SteamAPICall_t FileShare( const char *pchFile )
 {
     PRINT_DEBUG("Steam_Remote_Storage::FileShare\n");
+    if (!pchFile) return k_uAPICallInvalid;
     std::lock_guard<std::recursive_mutex> lock(global_mutex);
     RemoteStorageFileShareResult_t data = {};
     if (local_storage->file_exists(Local_Storage::remote_storage_folder, pchFile)) {