diff --git a/src/addrdb.cpp b/src/addrdb.cpp
--- a/src/addrdb.cpp
+++ b/src/addrdb.cpp
@@ -23,8 +23,8 @@
     // Write and commit header, data
     try {
         CHashWriter hasher(SER_DISK, CLIENT_VERSION);
-        stream << FLATDATA(chainParams.DiskMagic()) << data;
-        hasher << FLATDATA(chainParams.DiskMagic()) << data;
+        stream << chainParams.DiskMagic() << data;
+        hasher << chainParams.DiskMagic() << data;
         stream << hasher.GetHash();
     } catch (const std::exception &e) {
         return error("%s: Serialize or I/O error - %s", __func__, e.what());
@@ -73,7 +73,7 @@
         CHashVerifier<Stream> verifier(&stream);
         // de-serialize file header (network specific magic number) and ..
         uint8_t pchMsgTmp[4];
-        verifier >> FLATDATA(pchMsgTmp);
+        verifier >> pchMsgTmp;
         // ... verify the network matches ours
         if (memcmp(pchMsgTmp, std::begin(chainParams.DiskMagic()),
                    sizeof(pchMsgTmp))) {
diff --git a/src/netaddress.h b/src/netaddress.h
--- a/src/netaddress.h
+++ b/src/netaddress.h
@@ -114,7 +114,7 @@
 
     template <typename Stream, typename Operation>
     inline void SerializationOp(Stream &s, Operation ser_action) {
-        READWRITE(FLATDATA(ip));
+        READWRITE(ip);
     }
 
     friend class CSubNet;
@@ -153,8 +153,8 @@
     template <typename Stream, typename Operation>
     inline void SerializationOp(Stream &s, Operation ser_action) {
         READWRITE(network);
-        READWRITE(FLATDATA(netmask));
-        READWRITE(FLATDATA(valid));
+        READWRITE(netmask);
+        READWRITE(valid);
     }
 };
 
@@ -189,7 +189,7 @@
 
     template <typename Stream, typename Operation>
     inline void SerializationOp(Stream &s, Operation ser_action) {
-        READWRITE(FLATDATA(ip));
+        READWRITE(ip);
         unsigned short portN = htons(port);
         READWRITE(FLATDATA(portN));
         if (ser_action.ForRead()) {
diff --git a/src/protocol.h b/src/protocol.h
--- a/src/protocol.h
+++ b/src/protocol.h
@@ -61,10 +61,10 @@
 
     template <typename Stream, typename Operation>
     inline void SerializationOp(Stream &s, Operation ser_action) {
-        READWRITE(FLATDATA(pchMessageStart));
-        READWRITE(FLATDATA(pchCommand));
+        READWRITE(pchMessageStart);
+        READWRITE(pchCommand);
         READWRITE(nMessageSize);
-        READWRITE(FLATDATA(pchChecksum));
+        READWRITE(pchChecksum);
     }
 
     MessageMagic pchMessageStart;
diff --git a/src/serialize.h b/src/serialize.h
--- a/src/serialize.h
+++ b/src/serialize.h
@@ -10,6 +10,7 @@
 #include <prevector.h>
 
 #include <algorithm>
+#include <array>
 #include <cassert>
 #include <cstdint>
 #include <cstring>
@@ -53,6 +54,20 @@
     return const_cast<T *>(val);
 }
 
+//! Safely convert odd char pointer types to standard ones.
+inline char *CharCast(char *c) {
+    return c;
+}
+inline char *CharCast(uint8_t *c) {
+    return (char *)c;
+}
+inline const char *CharCast(const char *c) {
+    return c;
+}
+inline const char *CharCast(const uint8_t *c) {
+    return (const char *)c;
+}
+
 /**
  * Lowest-level serialization and conversion.
  * @note Sizes of these types are verified in the tests
@@ -215,11 +230,35 @@
 template <typename Stream> inline void Serialize(Stream &s, double a) {
     ser_writedata64(s, ser_double_to_uint64(a));
 }
+template <typename Stream, size_t N>
+inline void Serialize(Stream &s, const int8_t (&a)[N]) {
+    s.write(a, N);
+}
+template <typename Stream, size_t N>
+inline void Serialize(Stream &s, const uint8_t (&a)[N]) {
+    s.write(CharCast(a), N);
+}
+template <typename Stream, size_t N>
+inline void Serialize(Stream &s, const std::array<int8_t, N> &a) {
+    s.write(a.data(), N);
+}
+template <typename Stream, size_t N>
+inline void Serialize(Stream &s, const std::array<uint8_t, N> &a) {
+    s.write(CharCast(a.data()), N);
+}
 #ifndef CHAR_EQUALS_INT8
 // TODO Get rid of bare char
 template <typename Stream> inline void Unserialize(Stream &s, char &a) {
     a = ser_readdata8(s);
 }
+template <typename Stream, size_t N>
+inline void Serialize(Stream &s, const char (&a)[N]) {
+    s.write(a, N);
+}
+template <typename Stream, size_t N>
+inline void Serialize(Stream &s, const std::array<char, N> &a) {
+    s.write(a.data(), N);
+}
 #endif
 template <typename Stream> inline void Unserialize(Stream &s, int8_t &a) {
     a = ser_readdata8(s);
@@ -251,6 +290,32 @@
 template <typename Stream> inline void Unserialize(Stream &s, double &a) {
     a = ser_uint64_to_double(ser_readdata64(s));
 }
+template <typename Stream, size_t N>
+inline void Unserialize(Stream &s, int8_t (&a)[N]) {
+    s.read(a, N);
+}
+template <typename Stream, size_t N>
+inline void Unserialize(Stream &s, uint8_t (&a)[N]) {
+    s.read(CharCast(a), N);
+}
+template <typename Stream, size_t N>
+inline void Unserialize(Stream &s, std::array<int8_t, N> &a) {
+    s.read(a.data(), N);
+}
+template <typename Stream, size_t N>
+inline void Unserialize(Stream &s, std::array<uint8_t, N> &a) {
+    s.read(CharCast(a.data()), N);
+}
+#ifndef CHAR_EQUALS_INT8
+template <typename Stream, size_t N>
+inline void Unserialize(Stream &s, char (&a)[N]) {
+    s.read(CharCast(a), N);
+}
+template <typename Stream, size_t N>
+inline void Unserialize(Stream &s, std::array<char, N> &a) {
+    s.read(CharCast(a.data()), N);
+}
+#endif
 
 template <typename Stream> inline void Serialize(Stream &s, bool a) {
     char f = a;
diff --git a/src/test/net_tests.cpp b/src/test/net_tests.cpp
--- a/src/test/net_tests.cpp
+++ b/src/test/net_tests.cpp
@@ -74,7 +74,7 @@
 
 static CDataStream AddrmanToStream(CAddrManSerializationMock &_addrman) {
     CDataStream ssPeersIn(SER_DISK, CLIENT_VERSION);
-    ssPeersIn << FLATDATA(Params().DiskMagic());
+    ssPeersIn << Params().DiskMagic();
     ssPeersIn << _addrman;
     std::string str = ssPeersIn.str();
     std::vector<uint8_t> vchData(str.begin(), str.end());
@@ -118,7 +118,7 @@
     BOOST_CHECK(addrman1.size() == 0);
     try {
         uint8_t pchMsgTmp[4];
-        ssPeers1 >> FLATDATA(pchMsgTmp);
+        ssPeers1 >> pchMsgTmp;
         ssPeers1 >> addrman1;
     } catch (const std::exception &e) {
         exceptionThrown = true;
@@ -149,7 +149,7 @@
     BOOST_CHECK(addrman1.size() == 0);
     try {
         uint8_t pchMsgTmp[4];
-        ssPeers1 >> FLATDATA(pchMsgTmp);
+        ssPeers1 >> pchMsgTmp;
         ssPeers1 >> addrman1;
     } catch (const std::exception &e) {
         exceptionThrown = true;
diff --git a/src/test/serialize_tests.cpp b/src/test/serialize_tests.cpp
--- a/src/test/serialize_tests.cpp
+++ b/src/test/serialize_tests.cpp
@@ -22,7 +22,7 @@
     int intval;
     bool boolval;
     std::string stringval;
-    const char *charstrval;
+    char charstrval[16];
     CTransactionRef txval;
 
 public:
@@ -32,8 +32,9 @@
                                 const char *charstrvalin,
                                 const CTransactionRef &txvalin)
         : intval(intvalin), boolval(boolvalin),
-          stringval(std::move(stringvalin)), charstrval(charstrvalin),
-          txval(txvalin) {}
+          stringval(std::move(stringvalin)), txval(txvalin) {
+        memcpy(charstrval, charstrvalin, sizeof(charstrval));
+    }
 
     ADD_SERIALIZE_METHODS;
 
@@ -42,7 +43,7 @@
         READWRITE(intval);
         READWRITE(boolval);
         READWRITE(stringval);
-        READWRITE(FLATDATA(charstrval));
+        READWRITE(charstrval);
         READWRITE(txval);
     }
 
@@ -60,7 +61,7 @@
 
     template <typename Stream, typename Operation>
     inline void SerializationOp(Stream &s, Operation ser_action) {
-        READWRITE(intval, boolval, stringval, FLATDATA(charstrval), txval);
+        READWRITE(intval, boolval, stringval, charstrval, txval);
     }
 };
 
@@ -410,7 +411,7 @@
     int intval(100);
     bool boolval(true);
     std::string stringval("testing");
-    const char *charstrval("testing charstr");
+    const char charstrval[16] = "testing charstr";
     CMutableTransaction txval;
     CTransactionRef tx_ref{MakeTransactionRef(txval)};
     CSerializeMethodsTestSingle methodtest1(intval, boolval, stringval,
@@ -430,7 +431,7 @@
     BOOST_CHECK(methodtest3 == methodtest4);
 
     CDataStream ss2(SER_DISK, PROTOCOL_VERSION, intval, boolval, stringval,
-                    FLATDATA(charstrval), txval);
+                    charstrval, txval);
     ss2 >> methodtest3;
     BOOST_CHECK(methodtest3 == methodtest4);
 }
diff --git a/src/test/streams_tests.cpp b/src/test/streams_tests.cpp
--- a/src/test/streams_tests.cpp
+++ b/src/test/streams_tests.cpp
@@ -58,18 +58,16 @@
     BOOST_CHECK((vch == std::vector<uint8_t>{{0, 0, 0, 0, 1, 2}}));
     vch.clear();
 
-    CVectorWriter(SER_NETWORK, INIT_PROTO_VERSION, vch, 0, FLATDATA(bytes));
+    CVectorWriter(SER_NETWORK, INIT_PROTO_VERSION, vch, 0, bytes);
     BOOST_CHECK((vch == std::vector<uint8_t>{{3, 4, 5, 6}}));
-    CVectorWriter(SER_NETWORK, INIT_PROTO_VERSION, vch, 0, FLATDATA(bytes));
+    CVectorWriter(SER_NETWORK, INIT_PROTO_VERSION, vch, 0, bytes);
     BOOST_CHECK((vch == std::vector<uint8_t>{{3, 4, 5, 6}}));
     vch.clear();
 
     vch.resize(4, 8);
-    CVectorWriter(SER_NETWORK, INIT_PROTO_VERSION, vch, 2, a, FLATDATA(bytes),
-                  b);
+    CVectorWriter(SER_NETWORK, INIT_PROTO_VERSION, vch, 2, a, bytes, b);
     BOOST_CHECK((vch == std::vector<uint8_t>{{8, 8, 1, 3, 4, 5, 6, 2}}));
-    CVectorWriter(SER_NETWORK, INIT_PROTO_VERSION, vch, 2, a, FLATDATA(bytes),
-                  b);
+    CVectorWriter(SER_NETWORK, INIT_PROTO_VERSION, vch, 2, a, bytes, b);
     BOOST_CHECK((vch == std::vector<uint8_t>{{8, 8, 1, 3, 4, 5, 6, 2}}));
     vch.clear();
 }
diff --git a/src/validation.cpp b/src/validation.cpp
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -945,7 +945,7 @@
 
     // Write index header
     unsigned int nSize = GetSerializeSize(fileout, block);
-    fileout << FLATDATA(messageStart) << nSize;
+    fileout << messageStart << nSize;
 
     // Write block
     long fileOutPos = ftell(fileout.Get());
@@ -1357,7 +1357,7 @@
 
     // Write index header
     unsigned int nSize = GetSerializeSize(fileout, blockundo);
-    fileout << FLATDATA(messageStart) << nSize;
+    fileout << messageStart << nSize;
 
     // Write undo data
     long fileOutPos = ftell(fileout.Get());
@@ -5117,8 +5117,8 @@
                 uint8_t buf[CMessageHeader::MESSAGE_START_SIZE];
                 blkdat.FindByte(chainparams.DiskMagic()[0]);
                 nRewind = blkdat.GetPos() + 1;
-                blkdat >> FLATDATA(buf);
-                if (memcmp(buf, std::begin(chainparams.DiskMagic()),
+                blkdat >> buf;
+                if (memcmp(buf, chainparams.DiskMagic().data(),
                            CMessageHeader::MESSAGE_START_SIZE)) {
                     continue;
                 }