diff --git a/aegisub/libaegisub/common/charset_ucd.h b/aegisub/libaegisub/common/charset_ucd.h
index a3f148cab..b21e43c2b 100644
--- a/aegisub/libaegisub/common/charset_ucd.h
+++ b/aegisub/libaegisub/common/charset_ucd.h
@@ -19,6 +19,9 @@
 /// @ingroup libaegisub
 
 #ifndef LAGI_PRE
+#ifndef _WIN32
+#define _X86_ 1
+#endif
 #include "../../universalchardet/nscore.h"
 #include "../../universalchardet/nsUniversalDetector.h"
 #include "../../universalchardet/nsMBCSGroupProber.h"
diff --git a/aegisub/libaegisub/lagi_pre.h b/aegisub/libaegisub/lagi_pre.h
index 482d986de..5396536ba 100644
--- a/aegisub/libaegisub/lagi_pre.h
+++ b/aegisub/libaegisub/lagi_pre.h
@@ -41,6 +41,9 @@
 #include "libaegisub/cajun/writer.h"
 
 // Universalchardet
+#ifndef _WIN32
+#define _X86_ 1
+#endif
 #include "../universalchardet/nscore.h"
 #include "../universalchardet/nsUniversalDetector.h"
 #include "../universalchardet/nsMBCSGroupProber.h"