diff --git a/win32/FireflyShell/FireflyShell.cpp b/win32/FireflyShell/FireflyShell.cpp
index efdbde61..716252d4 100644
--- a/win32/FireflyShell/FireflyShell.cpp
+++ b/win32/FireflyShell/FireflyShell.cpp
@@ -176,7 +176,7 @@ BOOL CALLBACK Application::StaticWindowSearcher(HWND hwnd, LPARAM lparam)
 {
 	DWORD result;
     LRESULT ok = ::SendMessageTimeout(hwnd,
-                                      lparam,
+                                      static_cast<UINT>(lparam),
                                       0, 0, 
                                       SMTO_BLOCK |
                                       SMTO_ABORTIFHUNG,
diff --git a/win32/FireflyShell/ServerEvents.cpp b/win32/FireflyShell/ServerEvents.cpp
index 7228c83e..100f8d38 100644
--- a/win32/FireflyShell/ServerEvents.cpp
+++ b/win32/FireflyShell/ServerEvents.cpp
@@ -117,7 +117,7 @@ void ServerEvents::OnEvent(const void *buffer, size_t bytes_received)
 		UINT32 id = received[4] | (received[5] << 8) | (received[6] << 16) | (received[7] << 24);
 		UINT32 intval = received[8] | (received[9] << 8) | (received[10] << 16) | (received[11] << 24);
 
-		size_t string_length = bytes_received - 12;
+		int string_length = static_cast<int>(bytes_received) - 12;
 
 		if ((packet_size < bytes_received) && (packet_size >= 12))
 			string_length = packet_size - 12;