diff --git a/src/xz/message.c b/src/xz/message.c
index 88efb0c0..5dd9bc37 100644
--- a/src/xz/message.c
+++ b/src/xz/message.c
@@ -1016,7 +1016,8 @@ message_memlimit(void)
 		printf("%" PRIu64 "\n", hardware_memlimit_get());
 	else
 		printf(_("%s MiB (%s bytes)\n"),
-			uint64_to_str(hardware_memlimit_get() >> 20, 0),
+			uint64_to_str(
+				round_up_to_mib(hardware_memlimit_get()), 0),
 			uint64_to_str(hardware_memlimit_get(), 1));
 
 	tuklib_exit(E_SUCCESS, E_ERROR, verbosity != V_SILENT);
@@ -1180,7 +1181,7 @@ message_help(bool long_help)
 	if (long_help) {
 		printf(_(
 "On this system and configuration, this program will use a maximum of roughly\n"
-"%s MiB RAM and "), uint64_to_str(hardware_memlimit_get() / (1024 * 1024), 0));
+"%s MiB RAM and "), uint64_to_str(round_up_to_mib(hardware_memlimit_get()), 0));
 		printf(N_("one thread.\n\n", "%s threads.\n\n",
 				hardware_threadlimit_get()),
 				uint64_to_str(hardware_threadlimit_get(), 0));
diff --git a/src/xzdec/xzdec.c b/src/xzdec/xzdec.c
index 6ddf7d28..3b1ab0f1 100644
--- a/src/xzdec/xzdec.c
+++ b/src/xzdec/xzdec.c
@@ -66,6 +66,10 @@ my_errorf(const char *fmt, ...)
 static void lzma_attribute((noreturn))
 help(void)
 {
+	// Round up to the next MiB and do it correctly also with UINT64_MAX.
+	const uint64_t mem_mib = (memlimit >> 20)
+			+ ((memlimit & ((UINT32_C(1) << 20) - 1)) != 0);
+
 	printf(
 "Usage: %s [OPTION]... [FILE]...\n"
 "Uncompress files in the ." TOOL_FORMAT " format to the standard output.\n"
@@ -85,8 +89,7 @@ help(void)
 "%" PRIu64 " MiB RAM.\n"
 "\n"
 "Report bugs to <" PACKAGE_BUGREPORT "> (in English or Finnish).\n"
-PACKAGE_NAME " home page: <" PACKAGE_URL ">\n",
-		progname, memlimit / (1024 * 1024));
+PACKAGE_NAME " home page: <" PACKAGE_URL ">\n", progname, mem_mib);
 	tuklib_exit(EXIT_SUCCESS, EXIT_FAILURE, display_errors);
 }