diff --git a/doc/developer-notes.md b/doc/developer-notes.md
--- a/doc/developer-notes.md
+++ b/doc/developer-notes.md
@@ -93,7 +93,7 @@
         return didMore;
     }
 }
-}
+} // namespace foo
 ```
 
 
@@ -519,6 +519,21 @@
 
   - *Rationale*: Avoids symbol conflicts
 
+- Terminate namespaces with a comment (`// namespace mynamespace`). The comment
+  should be placed on the same line as the brace closing the namespace, e.g.
+
+```c++
+namespace mynamespace {
+    ...
+} // namespace mynamespace
+
+namespace {
+    ...
+} // namespace
+```
+
+  - *Rationale*: Avoids confusion about the namespace context
+
 Header Inclusions
 -----------------
 
diff --git a/src/.clang-format b/src/.clang-format
--- a/src/.clang-format
+++ b/src/.clang-format
@@ -13,6 +13,6 @@
 AllowShortBlocksOnASingleLine: false
 AllowShortIfStatementsOnASingleLine: true
 AllowShortFunctionsOnASingleLine: Inline
-FixNamespaceComments: false
+FixNamespaceComments: true
 ForEachMacros:   [ foreach, Q_FOREACH, BOOST_FOREACH, BOOST_REVERSE_FOREACH ]
 CommentPragmas:  '@DISABLE FORMATING FOR THIS COMMENT@'
diff --git a/src/addrdb.cpp b/src/addrdb.cpp
--- a/src/addrdb.cpp
+++ b/src/addrdb.cpp
@@ -111,7 +111,7 @@
     return DeserializeDB(chainParams, filein, data);
 }
 
-}
+} // namespace
 
 CBanDB::CBanDB(const CChainParams &chainParamsIn) : chainParams(chainParamsIn) {
     pathBanlist = GetDataDir() / "banlist.dat";
diff --git a/src/avalanche.h b/src/avalanche.h
--- a/src/avalanche.h
+++ b/src/avalanche.h
@@ -48,7 +48,7 @@
  * Special NodeId that represent no node.
  */
 static const NodeId NO_NODE = -1;
-}
+} // namespace
 
 /**
  * Vote history.
diff --git a/src/bench/bench.h b/src/bench/bench.h
--- a/src/bench/bench.h
+++ b/src/bench/bench.h
@@ -129,7 +129,7 @@
     int64_t m_width;
     int64_t m_height;
 };
-}
+} // namespace benchmark
 
 // BENCHMARK(foo, num_iters_for_one_second) expands to:  benchmark::BenchRunner
 // bench_11foo("foo", num_iterations);
diff --git a/src/bench/checkblock.cpp b/src/bench/checkblock.cpp
--- a/src/bench/checkblock.cpp
+++ b/src/bench/checkblock.cpp
@@ -11,7 +11,7 @@
 
 namespace block_bench {
 #include <bench/data/block413567.raw.h>
-}
+} // namespace block_bench
 
 // These are the two major time-sinks which happen after we have fully received
 // a block off the wire, but before we can relay the block on to peers using
diff --git a/src/crypto/sha256_avx2.cpp b/src/crypto/sha256_avx2.cpp
--- a/src/crypto/sha256_avx2.cpp
+++ b/src/crypto/sha256_avx2.cpp
@@ -101,7 +101,7 @@
         WriteLE32(out + 192 + offset, _mm256_extract_epi32(v, 1));
         WriteLE32(out + 224 + offset, _mm256_extract_epi32(v, 0));
     }
-}
+} // namespace
 
 void Transform_8way(uint8_t *out, const uint8_t *in) {
     // Transform 1
@@ -449,6 +449,6 @@
     Write8(out, 24, Add(g, K(0x1f83d9abul)));
     Write8(out, 28, Add(h, K(0x5be0cd19ul)));
 }
-}
+} // namespace sha256d64_avx2
 
 #endif
diff --git a/src/crypto/sha256_shani.cpp b/src/crypto/sha256_shani.cpp
--- a/src/crypto/sha256_shani.cpp
+++ b/src/crypto/sha256_shani.cpp
@@ -77,7 +77,7 @@
 inline void __attribute__((always_inline)) Save(uint8_t *out, __m128i s) {
     _mm_storeu_si128((__m128i *)out, _mm_shuffle_epi8(s, MASK));
 }
-}
+} // namespace
 
 namespace sha256_shani {
 void Transform(uint32_t *s, const uint8_t *chunk, size_t blocks) {
@@ -141,7 +141,7 @@
     _mm_storeu_si128((__m128i *)s, s0);
     _mm_storeu_si128((__m128i *)(s + 4), s1);
 }
-}
+} // namespace sha256_shani
 
 namespace sha256d64_shani {
 
@@ -353,6 +353,6 @@
     Save(out + 32, bs0);
     Save(out + 48, bs1);
 }
-}
+} // namespace sha256d64_shani
 
 #endif
diff --git a/src/crypto/sha256_sse4.cpp b/src/crypto/sha256_sse4.cpp
--- a/src/crypto/sha256_sse4.cpp
+++ b/src/crypto/sha256_sse4.cpp
@@ -952,7 +952,7 @@
         : "cc", "memory", "xmm0", "xmm1", "xmm2", "xmm3", "xmm4", "xmm5",
           "xmm6", "xmm7", "xmm8", "xmm9", "xmm10", "xmm11", "xmm12");
 }
-}
+} // namespace sha256_sse4
 
 /*
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
diff --git a/src/crypto/sha256_sse41.cpp b/src/crypto/sha256_sse41.cpp
--- a/src/crypto/sha256_sse41.cpp
+++ b/src/crypto/sha256_sse41.cpp
@@ -91,7 +91,7 @@
         WriteLE32(out + 64 + offset, _mm_extract_epi32(v, 1));
         WriteLE32(out + 96 + offset, _mm_extract_epi32(v, 0));
     }
-}
+} // namespace
 
 void Transform_4way(uint8_t *out, const uint8_t *in) {
     // Transform 1
@@ -439,6 +439,6 @@
     Write4(out, 24, Add(g, K(0x1f83d9abul)));
     Write4(out, 28, Add(h, K(0x5be0cd19ul)));
 }
-}
+} // namespace sha256d64_sse41
 
 #endif
diff --git a/src/fs.h b/src/fs.h
--- a/src/fs.h
+++ b/src/fs.h
@@ -18,6 +18,6 @@
 namespace fsbridge {
 FILE *fopen(const fs::path &p, const char *mode);
 FILE *freopen(const fs::path &p, const char *mode, FILE *stream);
-};
+}; // namespace fsbridge
 
 #endif // BITCOIN_FS_H
diff --git a/src/fs.cpp b/src/fs.cpp
--- a/src/fs.cpp
+++ b/src/fs.cpp
@@ -15,4 +15,4 @@
     return ::freopen(p.string().c_str(), mode, stream);
 }
 
-} // fsbridge
+} // namespace fsbridge
diff --git a/src/net_processing.cpp b/src/net_processing.cpp
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -3699,7 +3699,7 @@
         return mp->CompareDepthAndScore(*b, *a);
     }
 };
-}
+} // namespace
 
 bool PeerLogicValidation::SendMessages(const Config &config, CNode *pto,
                                        std::atomic<bool> &interruptMsgProc) {
diff --git a/src/qt/bitcoingui.h b/src/qt/bitcoingui.h
--- a/src/qt/bitcoingui.h
+++ b/src/qt/bitcoingui.h
@@ -38,7 +38,7 @@
 namespace interfaces {
 class Handler;
 class Node;
-}
+} // namespace interfaces
 
 QT_BEGIN_NAMESPACE
 class QAction;
diff --git a/src/qt/clientmodel.h b/src/qt/clientmodel.h
--- a/src/qt/clientmodel.h
+++ b/src/qt/clientmodel.h
@@ -20,7 +20,7 @@
 namespace interfaces {
 class Handler;
 class Node;
-}
+} // namespace interfaces
 
 QT_BEGIN_NAMESPACE
 class QTimer;
diff --git a/src/qt/splashscreen.h b/src/qt/splashscreen.h
--- a/src/qt/splashscreen.h
+++ b/src/qt/splashscreen.h
@@ -16,7 +16,7 @@
 class Handler;
 class Node;
 class Wallet;
-};
+}; // namespace interfaces
 
 /** Class for the splashscreen with information of the running client.
  *
diff --git a/src/qt/test/paymentservertests.cpp b/src/qt/test/paymentservertests.cpp
--- a/src/qt/test/paymentservertests.cpp
+++ b/src/qt/test/paymentservertests.cpp
@@ -7,12 +7,12 @@
 #include <amount.h>
 #include <interfaces/node.h>
 #include <qt/optionsmodel.h>
+#include <qt/test/paymentrequestdata.h>
 #include <random.h>
 #include <script/script.h>
 #include <script/standard.h>
 #include <util.h>
 #include <utilstrencodings.h>
-#include <qt/test/paymentrequestdata.h>
 
 #include <openssl/x509.h>
 #include <openssl/x509_vfy.h>
diff --git a/src/qt/test/wallettests.cpp b/src/qt/test/wallettests.cpp
--- a/src/qt/test/wallettests.cpp
+++ b/src/qt/test/wallettests.cpp
@@ -243,7 +243,7 @@
     QCOMPARE(requestTableModel->rowCount({}), currentRowCount - 1);
 }
 
-}
+} // namespace
 
 void WalletTests::walletTests() {
     TestGUI();
diff --git a/src/qt/transactiondesc.h b/src/qt/transactiondesc.h
--- a/src/qt/transactiondesc.h
+++ b/src/qt/transactiondesc.h
@@ -15,7 +15,7 @@
 class Wallet;
 struct WalletTx;
 struct WalletTxStatus;
-}
+} // namespace interfaces
 
 /**
  * Provide a human-readable extended HTML description of a transaction.
diff --git a/src/qt/transactionrecord.h b/src/qt/transactionrecord.h
--- a/src/qt/transactionrecord.h
+++ b/src/qt/transactionrecord.h
@@ -16,7 +16,7 @@
 class Wallet;
 struct WalletTx;
 struct WalletTxStatus;
-}
+} // namespace interfaces
 
 /**
  * UI model for transaction status. The transaction status is the part of a
diff --git a/src/qt/walletmodel.h b/src/qt/walletmodel.h
--- a/src/qt/walletmodel.h
+++ b/src/qt/walletmodel.h
@@ -31,7 +31,7 @@
 
 namespace interfaces {
 class Node;
-} // namespace interface
+} // namespace interfaces
 
 QT_BEGIN_NAMESPACE
 class QTimer;
diff --git a/src/qt/walletmodeltransaction.h b/src/qt/walletmodeltransaction.h
--- a/src/qt/walletmodeltransaction.h
+++ b/src/qt/walletmodeltransaction.h
@@ -14,7 +14,7 @@
 namespace interfaces {
 class Node;
 class PendingWalletTx;
-}
+} // namespace interfaces
 
 /** Data model for a walletmodel transaction. */
 class WalletModelTransaction {