diff --git a/alib2algo/src/grammar/generate/RandomGrammarFactory.cpp b/alib2algo/src/grammar/generate/RandomGrammarFactory.cpp
index 4626979f7906e4127fac57742d6ac097c8e7af9a..2e1044150ba63e9d576141f3e8ca5f27b51007ff 100644
--- a/alib2algo/src/grammar/generate/RandomGrammarFactory.cpp
+++ b/alib2algo/src/grammar/generate/RandomGrammarFactory.cpp
@@ -31,7 +31,7 @@ grammar::CFG < std::string, std::string > RandomGrammarFactory::generateCFG ( si
 		throw exception::CommonException("Too big nonterminals count.");
 
 	ext::deque < std::string > nonterminals;
-	for ( char i = 'a'; i <= 'z'; i ++ )
+	for ( char i = 'A'; i <= 'Z'; i ++ )
 		nonterminals.push_back ( std::string ( 1, i ) );
 
 	if ( randomizedAlphabet )