diff --git a/src/modules/MemoryUsagePrinter.cc b/src/modules/MemoryUsagePrinter.cc
index 0415b94..d285f49 100644
--- a/src/modules/MemoryUsagePrinter.cc
+++ b/src/modules/MemoryUsagePrinter.cc
@@ -89,7 +89,7 @@ class MemoryUsagePrinter: public Base {
     void update()
     {
         read_meminfo();
-        if (UNLIKELY(memtotal == -1))
+        if (UNLIKELY(memtotal == static_cast<std::size_t>(-1) ))
             memtotal = get_memusage("MemTotal"sv);
     }
     void do_print(const char *format)