diff --git a/src/msgb.c b/src/msgb.c
index 5a154e5..940135f 100644
--- a/src/msgb.c
+++ b/src/msgb.c
@@ -522,10 +522,11 @@
  */
 char *msgb_hexdump_c(const void *ctx, const struct msgb *msg)
 {
-	char *buf = talloc_size(ctx, msgb_length(msg)*3 + 100);
+	size_t buf_len = msgb_length(msg) * 3 + 100;
+	char *buf = talloc_size(ctx, buf_len);
 	if (!buf)
 		return NULL;
-	return msgb_hexdump_buf(buf, sizeof(buf), msg);
+	return msgb_hexdump_buf(buf, buf_len, msg);
 }
 
 /*! Print a string to the end of message buffer.
diff --git a/src/socket.c b/src/socket.c
index c817e72..7c412b6 100644
--- a/src/socket.c
+++ b/src/socket.c
@@ -837,7 +837,7 @@
 	char *str = talloc_size(ctx, OSMO_SOCK_NAME_MAXLEN);
 	if (!str)
 		return NULL;
-	osmo_sock_get_name_buf(str, sizeof(str), fd);
+	osmo_sock_get_name_buf(str, OSMO_SOCK_NAME_MAXLEN, fd);
 	return str;
 }
 
diff --git a/src/utils.c b/src/utils.c
index 896e917..b66721e 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -351,10 +351,11 @@
  */
 char *osmo_hexdump_c(const void *ctx, const unsigned char *buf, int len)
 {
-	char *hexd_buff = talloc_size(ctx, len*3 + 1);
+	size_t hexd_buff_len = len * 3 + 1;
+	char *hexd_buff = talloc_size(ctx, hexd_buff_len);
 	if (!hexd_buff)
 		return NULL;
-	osmo_hexdump_buf(hexd_buff, sizeof(hexd_buff), buf, len, " ", true);
+	osmo_hexdump_buf(hexd_buff, hexd_buff_len, buf, len, " ", true);
 	return hexd_buff;
 }
 
@@ -389,10 +390,11 @@
  */
 char *osmo_hexdump_nospc_c(const void *ctx, const unsigned char *buf, int len)
 {
-	char *hexd_buff = talloc_size(ctx, len*2 + 1);
+	size_t hexd_buff_len = len * 2 + 1;
+	char *hexd_buff = talloc_size(ctx, hexd_buff_len);
 	if (!hexd_buff)
 		return NULL;
-	osmo_hexdump_buf(hexd_buff, sizeof(hexd_buff), buf, len, "", true);
+	osmo_hexdump_buf(hexd_buff, hexd_buff_len, buf, len, "", true);
 	return hexd_buff;
 }
 
@@ -908,10 +910,11 @@
  */
 char *osmo_str_tolower_c(const void *ctx, const char *src)
 {
-	char *buf = talloc_size(ctx, strlen(src)+1);
+	size_t buf_len = strlen(src) + 1;
+	char *buf = talloc_size(ctx, buf_len);
 	if (!buf)
 		return NULL;
-	osmo_str_tolower_buf(buf, sizeof(buf), src);
+	osmo_str_tolower_buf(buf, buf_len, src);
 	return buf;
 }
 
@@ -966,10 +969,11 @@
  */
 char *osmo_str_toupper_c(const void *ctx, const char *src)
 {
-	char *buf = talloc_size(ctx, strlen(src)+1);
+	size_t buf_len = strlen(src) + 1;
+	char *buf = talloc_size(ctx, buf_len);
 	if (!buf)
 		return NULL;
-	osmo_str_toupper_buf(buf, sizeof(buf), src);
+	osmo_str_toupper_buf(buf, buf_len, src);
 	return buf;
 }