diff --git a/stepmania/src/RageUtil.cpp b/stepmania/src/RageUtil.cpp
index 66796e658a..36611faca1 100644
--- a/stepmania/src/RageUtil.cpp
+++ b/stepmania/src/RageUtil.cpp
@@ -1623,7 +1623,7 @@ RString Capitalize( const RString &s )
 	return s2;
 }
 
-char char_traits_char_nocase::uptab[256] =
+unsigned char char_traits_char_nocase::uptab[256] =
 {
 	0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E,0x0F,
 	0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,0x18,0x19,0x1A,0x1B,0x1C,0x1D,0x1E,0x1F,
diff --git a/stepmania/src/RageUtil.h b/stepmania/src/RageUtil.h
index 6d248f0769..142351d5d9 100644
--- a/stepmania/src/RageUtil.h
+++ b/stepmania/src/RageUtil.h
@@ -404,7 +404,7 @@ RString Capitalize( const RString &s );
 /* ASCII-only case insensitivity. */
 struct char_traits_char_nocase: public char_traits<char>
 {
-	static char uptab[256];
+	static unsigned char uptab[256];
 
 	static inline bool eq( char c1, char c2 )
 	{ return uptab[(unsigned char)c1] == uptab[(unsigned char)c2]; }