diff --git a/src/sizenotifiable.cpp b/src/sizenotifiable.cpp
index f600379..c942fa0 100644
--- a/src/sizenotifiable.cpp
+++ b/src/sizenotifiable.cpp
@@ -3,7 +3,6 @@
 #include "sdlmain.hpp"
 #include <cassert>
 #include <ciso646>
-#include <algorithm>
 
 namespace cloonel {
 	namespace implem {
@@ -28,8 +27,7 @@ namespace cloonel {
 			assert(m_registered or not m_sdlmain);
 			m_registered = false;
 #endif
-			if (m_registered) {
-				assert(m_sdlmain);
+			if (m_sdlmain) {
 				m_sdlmain->UnregisterForResChange(m_id);
 			}
 		}
diff --git a/src/sizenotifiable.hpp b/src/sizenotifiable.hpp
index 27fdc11..c6382fb 100644
--- a/src/sizenotifiable.hpp
+++ b/src/sizenotifiable.hpp
@@ -22,6 +22,7 @@
 
 #include "vector.hpp"
 #include <cstddef>
+#include <algorithm>
 
 namespace cloonel {
 	class SizeRatio;