diff --git a/filters.cpp b/filters.cpp
index 47a91a33..9f4308ba 100644
--- a/filters.cpp
+++ b/filters.cpp
@@ -509,7 +509,8 @@ size_t RandomNumberSink::Put2(const byte *begin, size_t length, int messageEnd,
 
 size_t ArraySink::Put2(const byte *begin, size_t length, int messageEnd, bool blocking)
 {
-	memcpy(m_buf+m_total, begin, STDMIN(length, SaturatingSubtract(m_size, m_total)));
+	if (m_buf+m_total != begin)
+		memcpy(m_buf+m_total, begin, STDMIN(length, SaturatingSubtract(m_size, m_total)));
 	m_total += length;
 	return 0;
 }
diff --git a/words.h b/words.h
index fc835591..d5fda71d 100644
--- a/words.h
+++ b/words.h
@@ -20,7 +20,8 @@ inline void SetWords(word *r, word a, size_t n)
 
 inline void CopyWords(word *r, const word *a, size_t n)
 {
-	memcpy(r, a, n*WORD_SIZE);
+	if (r != a)
+		memcpy(r, a, n*WORD_SIZE);
 }
 
 inline void XorWords(word *r, const word *a, const word *b, size_t n)
diff --git a/zdeflate.cpp b/zdeflate.cpp
index 426e438a..ae5e1a76 100644
--- a/zdeflate.cpp
+++ b/zdeflate.cpp
@@ -221,6 +221,7 @@ Deflator::Deflator(BufferedTransformation *attachment, int deflateLevel, int log
 
 Deflator::Deflator(const NameValuePairs &parameters, BufferedTransformation *attachment)
 	: LowFirstBitWriter(attachment)
+	, m_deflateLevel(-1)
 {
 	InitializeStaticEncoders();
 	IsolatedInitialize(parameters);