diff -Naur spdlog-1.4.2.old/include/spdlog/details/circular_q.h spdlog-1.4.2/include/spdlog/details/circular_q.h
--- spdlog-1.4.2.old/include/spdlog/details/circular_q.h	2019-12-20 21:31:05.407421825 +0100
+++ spdlog-1.4.2/include/spdlog/details/circular_q.h	2019-12-20 21:31:40.882235267 +0100
@@ -5,6 +5,7 @@
 #pragma once
 
 #include <vector>
+#include <cassert>
 
 namespace spdlog {
 namespace details {
diff -Naur spdlog-1.4.2.old/include/spdlog/details/thread_pool-inl.h spdlog-1.4.2/include/spdlog/details/thread_pool-inl.h
--- spdlog-1.4.2.old/include/spdlog/details/thread_pool-inl.h	2019-12-20 21:31:05.407421825 +0100
+++ spdlog-1.4.2/include/spdlog/details/thread_pool-inl.h	2019-12-20 21:32:15.390516965 +0100
@@ -8,6 +8,7 @@
 #endif
 
 #include "spdlog/common.h"
+#include <cassert>
 
 namespace spdlog {
 namespace details {