diff --git a/misc.h b/misc.h
index 3dfff68f..7a9cbd68 100644
--- a/misc.h
+++ b/misc.h
@@ -867,7 +867,7 @@ inline T2 ModPowerOf2(const T1 &a, const T2 &b)
 {
 	CRYPTOPP_ASSERT(IsPowerOf2(b));
 	// Coverity finding CID 170383 Overflowed return value (INTEGER_OVERFLOW)
-	return T2(a) & SaturatingSubtract(b,1);
+	return T2(a) & SaturatingSubtract(b,1U);
 }
 
 //! \brief Rounds a value down to a multiple of a second value
diff --git a/vmac.h b/vmac.h
index 0723b1c4..3c6bb858 100644
--- a/vmac.h
+++ b/vmac.h
@@ -61,7 +61,7 @@ protected:
 	CRYPTOPP_BLOCKS_END(6)
 
 	bool m_is128, m_padCached, m_isFirstBlock;
-	int m_L1KeyLength;
+	unsigned int m_L1KeyLength;
 };
 
 //! \class VMAC