diff --git a/stepmania/src/Profile.cpp b/stepmania/src/Profile.cpp
index 318cb05d0d..8d04799d06 100644
--- a/stepmania/src/Profile.cpp
+++ b/stepmania/src/Profile.cpp
@@ -89,7 +89,7 @@ void Profile::InitEditableData()
 RString Profile::MakeGuid()
 {
 	RString s;
-	s.resize( GUID_SIZE_BYTES );
+	s.reserve( GUID_SIZE_BYTES*2 );
 	char buf[GUID_SIZE_BYTES];
 	CryptManager::GetRandomBytes( buf, GUID_SIZE_BYTES );
 	for( unsigned i=0; i<GUID_SIZE_BYTES; i++ )