diff --git a/src/Font.cpp b/src/Font.cpp
index 8ae5ded02a..731c0b651c 100644
--- a/src/Font.cpp
+++ b/src/Font.cpp
@@ -352,8 +352,16 @@ const glyph &Font::GetGlyph( wchar_t c ) const
 	 * with non-roman song titles, and looking at it, I'm gonna guess that
 	 * this is how ITG2 prevented crashing with them --infamouspat */
 	//ASSERT(c >= 0 && c <= 0xFFFFFF);
-	if (c < 0 || c > 0xFFFFFF)
+
+	// wchar_t can be signed or unsigned depending on the platform and the compiler.
+	// We use WCHAR_MIN to determine a valid condition that won't emit a type-limits warning.
+	#if WCHAR_MIN != 0
+	if (c < 0 || c > 0xFFFFFF) {
+	#else
+	if (c > 0xFFFFFF) {
+	#endif
 		c = 1;
+	}
 
 	// Fast path:
 	if( c < (int) ARRAYLEN(m_iCharToGlyphCache) && m_iCharToGlyphCache[c] )
diff --git a/src/ModelTypes.h b/src/ModelTypes.h
index 5d11063305..b279f29847 100644
--- a/src/ModelTypes.h
+++ b/src/ModelTypes.h
@@ -18,14 +18,14 @@ struct msTriangle
 struct msMesh
 {
 	RString			sName;
-	char			nMaterialIndex;
+	std::int8_t			nMaterialIndex;
 
 	std::vector<RageModelVertex>	Vertices;
 
 	// OPTIMIZATION: If all verts in a mesh are transformed by the same bone,
 	// then send the transform to the graphics card for the whole mesh instead
 	// of transforming each vertex on the CPU;
-	char			m_iBoneIndex;	// -1 = no bone
+	std::int8_t			m_iBoneIndex;	// -1 = no bone
 
 	std::vector<msTriangle>	Triangles;
 };
diff --git a/src/RageUtil.cpp b/src/RageUtil.cpp
index 04c845db8f..cf525a8b71 100644
--- a/src/RageUtil.cpp
+++ b/src/RageUtil.cpp
@@ -1831,8 +1831,15 @@ void UnicodeUpperLower( wchar_t *p, std::size_t iLen, const unsigned char pMappi
 	wchar_t *pEnd = p + iLen;
 	while( p != pEnd )
 	{
-		if( *p >= 0 && *p < 256 )
+		// wchar_t can be signed or unsigned depending on the platform and the compiler.
+		// We use WCHAR_MIN to determine a valid condition that won't emit a type-limits warning.
+		#if WCHAR_MIN != 0
+		if( *p >= 0 && *p < 256 ) {
+		#else
+		if( *p < 256 ) {
+		#endif
 			*p = pMapping[*p];
+		}
 		++p;
 	}
 }