Help with YACC

[Michael Stone]

When compiling a grammar file as shown below,

    yacc -v -d grammar.y20

I receive the following error message,

fatal error: too many terminals, limit 127, line 232

y.output contains,

127/127 terminals, 0/300 nonterminals
1/600 grammar rules, 0/750 states
0 shift/reduce, 0 reduce/reduce conflicts reported
0/350 working sets used
memory: states,etc. 0/12000, parser 0/12000
0/600 distinct lookahead sets
0 extra closures
0 shift entries, 0 exceptions
0 goto entries
0 entries saved by goto default

Does anyone know how to change the terminals setting to allow for more?

Thanks in advance.