diff --git a/ida.cpp b/ida.cpp
index 1c8b3ab2..30d7381b 100644
--- a/ida.cpp
+++ b/ida.cpp
@@ -250,7 +250,7 @@ size_t SecretSharing::Put2(const byte *begin, size_t length, int messageEnd, boo
 	if (!blocking)
 		throw BlockingInputOnly("SecretSharing");
 
-	SecByteBlock buf(UnsignedMin(256, length));
+	SecByteBlock buf(UnsignedMin(256u, length));
 	unsigned int threshold = m_ida.GetThreshold();
 	while (length > 0)
 	{
diff --git a/misc.h b/misc.h
index f72bc615..1f6f80de 100644
--- a/misc.h
+++ b/misc.h
@@ -14,6 +14,10 @@
 #include "stdcpp.h"
 #include "trap.h"
 
+#if defined(CRYPTOPP_CXX11)
+# include <type_traits>
+#endif
+
 #if !defined(CRYPTOPP_DOXYGEN_PROCESSING)
 
 #if (CRYPTOPP_MSC_VERSION)
@@ -695,6 +699,12 @@ template <class T> inline const T& STDMAX(const T& a, const T& b)
 template <class T1, class T2> inline const T1 UnsignedMin(const T1& a, const T2& b)
 {
 	CRYPTOPP_COMPILE_ASSERT((sizeof(T1)<=sizeof(T2) && T2(-1)>0) || (sizeof(T1)>sizeof(T2) && T1(-1)>0));
+
+#if defined(CRYPTOPP_CXX11)
+	CRYPTOPP_COMPILE_ASSERT(std::is_unsigned_v<T1> == true);
+	CRYPTOPP_COMPILE_ASSERT(std::is_unsigned_v<T2> == true);
+#endif
+
 	if (sizeof(T1)<=sizeof(T2))
 		return b < (T2)a ? (T1)b : a;
 	else
diff --git a/randpool.cpp b/randpool.cpp
index bda49ec0..2cac4eeb 100644
--- a/randpool.cpp
+++ b/randpool.cpp
@@ -68,7 +68,7 @@ void RandomPool::GenerateIntoBufferedTransformation(BufferedTransformation &targ
 		do
 		{
 			m_pCipher->ProcessBlock(m_seed);
-			size_t len = UnsignedMin(16, size);
+			size_t len = UnsignedMin(16u, size);
 			target.ChannelPut(channel, m_seed, len);
 			size -= len;
 		} while (size > 0);