diff --git a/util/nvramtool/cmos_lowlevel.c b/util/nvramtool/cmos_lowlevel.c
index ef0c383..618e8d2 100644
--- a/util/nvramtool/cmos_lowlevel.c
+++ b/util/nvramtool/cmos_lowlevel.c
@@ -125,13 +125,16 @@
 	result = 0;
 
 	if (e->config == CMOS_ENTRY_STRING) {
-		char *newstring = calloc(1, (length + 7) / 8);
+		int strsz = (length + 7) / 8;
+		char *newstring = alloca(strsz);
 		unsigned usize = (8 * sizeof(unsigned long long));
 
 		if (!newstring) {
 			out_of_memory();
 		}
 
+		memset(newstring, 0, strsz);
+
 		for (next_bit = 0, bits_left = length;
 		     bits_left; next_bit += nr_bits, bits_left -= nr_bits) {
 			nr_bits = cmos_bit_op_strategy(bit + next_bit,