diff --git a/include/tbuf.h b/include/tbuf.h
index 791373fe6a38d07eff46c0d489c1cf860c6da379..12beb423393e5b38a87d9ee2616204ae53a3dfb7 100644
--- a/include/tbuf.h
+++ b/include/tbuf.h
@@ -40,9 +40,9 @@ extern "C" {
 
 struct tbuf {
 	/* Used space in the buffer. */
-	uint32_t size;
+	size_t size;
 	/* Total allocated buffer capacity. */
-	uint32_t capacity;
+	size_t capacity;
 	/* Allocated buffer. */
 	char *data;
 	struct palloc_pool *pool;
diff --git a/src/admin.cc b/src/admin.cc
index 9670a9250b8bd6a49a330899fde18a51156dc4d0..f6b5caf6523c0fb886c1970d703d4fb8b48691d7 100644
--- a/src/admin.cc
+++ b/src/admin.cc
@@ -171,7 +171,7 @@ static void
 fail(struct tbuf *out, struct tbuf *err)
 {
 	start(out);
-	tbuf_printf(out, "fail:%.*s" CRLF, err->size, (char *)err->data);
+	tbuf_printf(out, "fail:%.*s" CRLF, (uint32_t)err->size, (char *)err->data);
 	end(out);
 }
 
diff --git a/src/tarantool.cc b/src/tarantool.cc
index ea433395cc447a23a838f00b8a30152abf9d4ac2..3f9e029a9251dd10770d795e1b5a0c62d5043ca9 100644
--- a/src/tarantool.cc
+++ b/src/tarantool.cc
@@ -786,7 +786,7 @@ main(int argc, char **argv)
 	if (gopt(opt, 'k')) {
 		if (fill_default_tarantool_cfg(&cfg) != 0 || load_cfg(&cfg, 0) != 0) {
 			say_error("check_config FAILED"
-				  "%.*s", cfg_out->size, (char *)cfg_out->data);
+				  "%.*s", (uint32_t)cfg_out->size, (char *)cfg_out->data);
 
 			return 1;
 		}
@@ -796,7 +796,7 @@ main(int argc, char **argv)
 
 	if (fill_default_tarantool_cfg(&cfg) != 0 || load_cfg(&cfg, 0) != 0)
 		panic("can't load config:"
-		      "%.*s", cfg_out->size, (char *)cfg_out->data);
+		      "%.*s", (uint32_t)cfg_out->size, (char *)cfg_out->data);
 
 	if (gopt_arg(opt, 'g', &cfg_paramname)) {
 		tarantool_cfg_iterator_t *i;
diff --git a/src/tbuf.c b/src/tbuf.c
index 74631d9f99805c2cf79c4a92c7c77a5823b6cc1e..638fad4d51e3a6e2a135a30b96bcce69fdcf2e31 100644
--- a/src/tbuf.c
+++ b/src/tbuf.c
@@ -75,7 +75,7 @@ tbuf_ensure_resize(struct tbuf *e, size_t required)
 	tbuf_assert(e);
 
 	/* Make new capacity a multiple of alloc factor. */
-	size_t new_capacity = MAX(e->capacity, (uint32_t)TBUF_ALLOC_FACTOR) * 2;
+	size_t new_capacity = MAX(e->capacity, (size_t)TBUF_ALLOC_FACTOR) * 2;
 
 	while (new_capacity < e->size + required)
 		new_capacity *= 2;