diff --git a/src/sound/adlmidi/adlmidi_private.hpp b/src/sound/adlmidi/adlmidi_private.hpp
index 852334328..eace3a736 100644
--- a/src/sound/adlmidi/adlmidi_private.hpp
+++ b/src/sound/adlmidi/adlmidi_private.hpp
@@ -109,6 +109,7 @@ typedef int32_t ssize_t;
 #pragma warning(disable:4267)
 #pragma warning(disable:4244)
 #pragma warning(disable:4146)
+#pragma warning(disable:4800)
 #endif
 
 #include "fraction.hpp"
diff --git a/src/sound/opnmidi/opnmidi_private.hpp b/src/sound/opnmidi/opnmidi_private.hpp
index 10cda9716..6e956d10f 100644
--- a/src/sound/opnmidi/opnmidi_private.hpp
+++ b/src/sound/opnmidi/opnmidi_private.hpp
@@ -81,6 +81,7 @@ typedef __int32 ssize_t;
 #pragma warning(disable:4244)
 #pragma warning(disable:4267)
 #pragma warning(disable:4146)
+#pragma warning(disable:4800)
 #endif