diff --git a/lib/crypto_backend/base64.c b/lib/crypto_backend/base64.c
index 5e489b95..d9733a09 100644
--- a/lib/crypto_backend/base64.c
+++ b/lib/crypto_backend/base64.c
@@ -19,7 +19,7 @@
 /* https://tools.ietf.org/html/rfc4648#section-4 */
 static char base64char(int x)
 {
-	static const char table[64] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+	static const char table[65] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 				      "abcdefghijklmnopqrstuvwxyz"
 				      "0123456789+/";
 	return table[x & 63];
diff --git a/lib/utils_wipe.c b/lib/utils_wipe.c
index 6ab2f36a..6a26dedf 100644
--- a/lib/utils_wipe.c
+++ b/lib/utils_wipe.c
@@ -50,7 +50,7 @@ static void wipeSpecial(char *buffer, size_t buffer_size, unsigned int turn)
 {
 	unsigned int i;
 
-	unsigned char write_modes[][3] = {
+	const unsigned char write_modes[27][4] = {
 		{"\x55\x55\x55"}, {"\xaa\xaa\xaa"}, {"\x92\x49\x24"},
 		{"\x49\x24\x92"}, {"\x24\x92\x49"}, {"\x00\x00\x00"},
 		{"\x11\x11\x11"}, {"\x22\x22\x22"}, {"\x33\x33\x33"},