diff --git a/frontends/verilog/verilog_lexer.l b/frontends/verilog/verilog_lexer.l
index f9118e142..1b1873e24 100644
--- a/frontends/verilog/verilog_lexer.l
+++ b/frontends/verilog/verilog_lexer.l
@@ -274,7 +274,7 @@ YOSYS_NAMESPACE_END
 		yystr[j++] = yystr[i++];
 	}
 	yystr[j] = 0;
-	frontend_verilog_yylval.string = new std::string(yystr);
+	frontend_verilog_yylval.string = new std::string(yystr, j);
 	free(yystr);
 	return TOK_STRING;
 }