diff --git a/console-server.c b/console-server.c
index 803262b..bcbd4db 100644
--- a/console-server.c
+++ b/console-server.c
@@ -82,7 +82,7 @@
 };
 
 /* size of the shared backlog ringbuffer */
-const size_t buffer_size = 128 * 1024;
+const size_t buffer_size = 128ul * 1024ul;
 
 /* state shared with the signal handler */
 static bool sigint;
diff --git a/log-handler.c b/log-handler.c
index 4e2425f..233f41f 100644
--- a/log-handler.c
+++ b/log-handler.c
@@ -43,7 +43,7 @@
 };
 
 static const char *default_filename = LOCALSTATEDIR "/log/obmc-console.log";
-static const size_t default_logsize = 16 * 1024;
+static const size_t default_logsize = 16ul * 1024ul;
 
 static struct log_handler *to_log_handler(struct handler *handler)
 {
diff --git a/test/test-config-parse-logsize.c b/test/test-config-parse-logsize.c
index 482932e..9bd4f79 100644
--- a/test/test-config-parse-logsize.c
+++ b/test/test-config-parse-logsize.c
@@ -21,15 +21,15 @@
 	const struct test_parse_size_unit test_data[] = {
 		{ "0", 0, -1 },
 		{ "1", 1, 0 },
-		{ "4k", 4 * 1024, 0 },
+		{ "4k", 4ul * 1024ul, 0 },
 		{ "6M", (6ul << 20), 0 },
 		{ "4095M", (4095ul << 20), 0 },
 		{ "2G", (2ul << 30), 0 },
 		{ "8M\n", (8ul << 20), 0 }, /* Suffix ignored */
-		{ " 10k", 10 * 1024, 0 }, /* Leading spaces trimmed */
-		{ "10k ", 10 * 1024, 0 }, /* Trailing spaces trimmed */
-		{ "\r\t10k \r\t", 10 * 1024, 0 }, /* Spaces trimmed */
-		{ " 10 kB ", 10 * 1024, 0 }, /* Spaces trimmed */
+		{ " 10k", 10ul * 1024ul, 0 }, /* Leading spaces trimmed */
+		{ "10k ", 10ul * 1024ul, 0 }, /* Trailing spaces trimmed */
+		{ "\r\t10k \r\t", 10ul * 1024ul, 0 }, /* Spaces trimmed */
+		{ " 10 kB ", 10ul * 1024ul, 0 }, /* Spaces trimmed */
 		{ "11G", 0, -1 }, /* Overflow */
 		{ "4294967296", 0, -1 }, /* Overflow */
 		{ "4096M", 0, -1 }, /* Overflow */