diff --git a/dll/shellext/shellbtrfs/balance.cpp b/dll/shellext/shellbtrfs/balance.cpp
index aa639a57d0c..edcfecea511 100644
--- a/dll/shellext/shellbtrfs/balance.cpp
+++ b/dll/shellext/shellbtrfs/balance.cpp
@@ -1090,6 +1090,10 @@ static void unserialize(void* data, ULONG len, WCHAR* s) {
     }
 }
 
+#ifdef __REACTOS__
+extern "C" {
+#endif
+
 void CALLBACK StartBalanceW(HWND hwnd, HINSTANCE hinst, LPWSTR lpszCmdLine, int nCmdShow) {
     WCHAR *s, *vol, *block;
     HANDLE h, token;
@@ -1291,3 +1295,7 @@ void CALLBACK StopBalanceW(HWND hwnd, HINSTANCE hinst, LPWSTR lpszCmdLine, int n
 end:
     CloseHandle(token);
 }
+
+#ifdef __REACTOS__
+} /* extern "C" */
+#endif
diff --git a/dll/shellext/shellbtrfs/contextmenu.cpp b/dll/shellext/shellbtrfs/contextmenu.cpp
index a306190799c..a5769be5500 100644
--- a/dll/shellext/shellbtrfs/contextmenu.cpp
+++ b/dll/shellext/shellbtrfs/contextmenu.cpp
@@ -1718,6 +1718,10 @@ end:
     CloseHandle(source);
 }
 
+#ifdef __REACTOS__
+extern "C" {
+#endif
+
 void CALLBACK ReflinkCopyW(HWND hwnd, HINSTANCE hinst, LPWSTR lpszCmdLine, int nCmdShow) {
     LPWSTR* args;
     int num_args;
@@ -1796,3 +1800,7 @@ void CALLBACK ReflinkCopyW(HWND hwnd, HINSTANCE hinst, LPWSTR lpszCmdLine, int n
 end:
     LocalFree(args);
 }
+
+#ifdef __REACTOS__
+} /* extern "C" */
+#endif
diff --git a/dll/shellext/shellbtrfs/recv.cpp b/dll/shellext/shellbtrfs/recv.cpp
index 5c1ab3646eb..f52a0092a4f 100644
--- a/dll/shellext/shellbtrfs/recv.cpp
+++ b/dll/shellext/shellbtrfs/recv.cpp
@@ -1987,6 +1987,10 @@ void BtrfsRecv::Open(HWND hwnd, WCHAR* file, WCHAR* path, BOOL quiet) {
     }
 }
 
+#ifdef __REACTOS__
+extern "C" {
+#endif
+
 void CALLBACK RecvSubvolGUIW(HWND hwnd, HINSTANCE hinst, LPWSTR lpszCmdLine, int nCmdShow) {
     OPENFILENAMEW ofn;
     WCHAR file[MAX_PATH];
@@ -2145,3 +2149,7 @@ void CALLBACK RecvSubvolW(HWND hwnd, HINSTANCE hinst, LPWSTR lpszCmdLine, int nC
 end:
     LocalFree(args);
 }
+
+#ifdef __REACTOS__
+} /* extern "C" */
+#endif
diff --git a/dll/shellext/shellbtrfs/scrub.cpp b/dll/shellext/shellbtrfs/scrub.cpp
index 87359a55618..1faaa9ec5d0 100644
--- a/dll/shellext/shellbtrfs/scrub.cpp
+++ b/dll/shellext/shellbtrfs/scrub.cpp
@@ -566,6 +566,10 @@ static INT_PTR CALLBACK stub_ScrubDlgProc(HWND hwndDlg, UINT uMsg, WPARAM wParam
         return FALSE;
 }
 
+#ifdef __REACTOS__
+extern "C" {
+#endif
+
 void CALLBACK ShowScrubW(HWND hwnd, HINSTANCE hinst, LPWSTR lpszCmdLine, int nCmdShow) {
     HANDLE token;
     TOKEN_PRIVILEGES tp;
@@ -694,3 +698,7 @@ void CALLBACK StopScrubW(HWND hwnd, HINSTANCE hinst, LPWSTR lpszCmdLine, int nCm
 end:
     LocalFree(args);
 }
+
+#ifdef __REACTOS__
+} /* extern "C" */
+#endif
diff --git a/dll/shellext/shellbtrfs/send.cpp b/dll/shellext/shellbtrfs/send.cpp
index cbe5f7e26c1..a1ab8b49b60 100644
--- a/dll/shellext/shellbtrfs/send.cpp
+++ b/dll/shellext/shellbtrfs/send.cpp
@@ -547,6 +547,10 @@ void BtrfsSend::Open(HWND hwnd, LPWSTR path) {
         ShowError(hwnd, GetLastError());
 }
 
+#ifdef __REACTOS__
+extern "C" {
+#endif
+
 void CALLBACK SendSubvolGUIW(HWND hwnd, HINSTANCE hinst, LPWSTR lpszCmdLine, int nCmdShow) {
     HANDLE token;
     TOKEN_PRIVILEGES tp;
@@ -585,6 +589,10 @@ void CALLBACK SendSubvolGUIW(HWND hwnd, HINSTANCE hinst, LPWSTR lpszCmdLine, int
     CloseHandle(token);
 }
 
+#ifdef __REACTOS__
+} /* extern "C" */
+#endif
+
 static void send_subvol(std::wstring subvol, std::wstring file, std::wstring parent, std::vector<std::wstring> clones) {
     char* buf;
     HANDLE dirh, stream;
@@ -697,6 +705,10 @@ end3:
     free(buf);
 }
 
+#ifdef __REACTOS__
+extern "C" {
+#endif
+
 void CALLBACK SendSubvolW(HWND hwnd, HINSTANCE hinst, LPWSTR lpszCmdLine, int nCmdShow) {
     LPWSTR* args;
     int num_args;
@@ -755,3 +767,7 @@ void CALLBACK SendSubvolW(HWND hwnd, HINSTANCE hinst, LPWSTR lpszCmdLine, int nC
 end:
     LocalFree(args);
 }
+
+#ifdef __REACTOS__
+} /* extern "C" */
+#endif