frontends/verilog/verilog_parser.tab.hh: frontends/verilog/verilog_parser.tab.cc
-frontends/verilog/verilog_lexer.cc: frontends/verilog/verilog_lexer.l
+frontends/verilog/verilog_lexer.cc: frontends/verilog/verilog_lexer.l frontends/verilog/verilog_parser.tab.cc
$(Q) mkdir -p $(dir $@)
$(P) flex -o frontends/verilog/verilog_lexer.cc $<