diff --git a/src/crypto/chacha20.cpp b/src/crypto/chacha20.cpp
index e756e0431e2..b1bd3c54907 100644
--- a/src/crypto/chacha20.cpp
+++ b/src/crypto/chacha20.cpp
@@ -59,7 +59,7 @@ void ChaCha20Aligned::Seek(Nonce96 nonce, uint32_t block_counter) noexcept
 
 inline void ChaCha20Aligned::Keystream(Span<std::byte> output) noexcept
 {
-    unsigned char* c = UCharCast(output.data());
+    std::byte* c = output.data();
     size_t blocks = output.size() / BLOCKLEN;
     assert(blocks * BLOCKLEN == output.size());
 
@@ -161,8 +161,8 @@ inline void ChaCha20Aligned::Keystream(Span<std::byte> output) noexcept
 inline void ChaCha20Aligned::Crypt(Span<const std::byte> in_bytes, Span<std::byte> out_bytes) noexcept
 {
     assert(in_bytes.size() == out_bytes.size());
-    const unsigned char* m = UCharCast(in_bytes.data());
-    unsigned char* c = UCharCast(out_bytes.data());
+    const std::byte* m = in_bytes.data();
+    std::byte* c = out_bytes.data();
     size_t blocks = out_bytes.size() / BLOCKLEN;
     assert(blocks * BLOCKLEN == out_bytes.size());
 
diff --git a/src/crypto/chacha20poly1305.cpp b/src/crypto/chacha20poly1305.cpp
index b969bb1a299..282f32a5e42 100644
--- a/src/crypto/chacha20poly1305.cpp
+++ b/src/crypto/chacha20poly1305.cpp
@@ -56,8 +56,8 @@ void ComputeTag(ChaCha20& chacha20, Span<const std::byte> aad, Span<const std::b
     poly1305.Update(cipher).Update(Span{PADDING}.first(cipher_padding_length));
     // - Process the AAD and plaintext length with Poly1305.
     std::byte length_desc[Poly1305::TAGLEN];
-    WriteLE64(UCharCast(length_desc), aad.size());
-    WriteLE64(UCharCast(length_desc + 8), cipher.size());
+    WriteLE64(length_desc, aad.size());
+    WriteLE64(length_desc + 8, cipher.size());
     poly1305.Update(length_desc);
 
     // Output tag.
diff --git a/src/crypto/sha3.cpp b/src/crypto/sha3.cpp
index 770500bfe27..56aaa4615e7 100644
--- a/src/crypto/sha3.cpp
+++ b/src/crypto/sha3.cpp
@@ -105,9 +105,9 @@ void KeccakF(uint64_t (&st)[25])
 
 SHA3_256& SHA3_256::Write(Span<const unsigned char> data)
 {
-    if (m_bufsize && m_bufsize + data.size() >= sizeof(m_buffer)) {
+    if (m_bufsize && data.size() >= sizeof(m_buffer) - m_bufsize) {
         // Fill the buffer and process it.
-        std::copy(data.begin(), data.begin() + sizeof(m_buffer) - m_bufsize, m_buffer + m_bufsize);
+        std::copy(data.begin(), data.begin() + (sizeof(m_buffer) - m_bufsize), m_buffer + m_bufsize);
         data = data.subspan(sizeof(m_buffer) - m_bufsize);
         m_state[m_pos++] ^= ReadLE64(m_buffer);
         m_bufsize = 0;
diff --git a/src/random.h b/src/random.h
index 2a26ca986be..203678b17c6 100644
--- a/src/random.h
+++ b/src/random.h
@@ -268,12 +268,12 @@ public:
     {
         while (span.size() >= 8) {
             uint64_t gen = Impl().rand64();
-            WriteLE64(UCharCast(span.data()), gen);
+            WriteLE64(span.data(), gen);
             span = span.subspan(8);
         }
         if (span.size() >= 4) {
             uint32_t gen = Impl().rand32();
-            WriteLE32(UCharCast(span.data()), gen);
+            WriteLE32(span.data(), gen);
             span = span.subspan(4);
         }
         while (span.size()) {
@@ -397,7 +397,7 @@ public:
         if (requires_seed) RandomSeed();
         std::array<std::byte, 8> buf;
         rng.Keystream(buf);
-        return ReadLE64(UCharCast(buf.data()));
+        return ReadLE64(buf.data());
     }
 
     /** Fill a byte Span with random bytes. This overrides the RandomMixin version. */
diff --git a/src/wallet/migrate.cpp b/src/wallet/migrate.cpp
index d7d85773743..d2c163027d2 100644
--- a/src/wallet/migrate.cpp
+++ b/src/wallet/migrate.cpp
@@ -603,7 +603,7 @@ void BerkeleyRODatabase::Open()
 
     // Read subdatabase page number
     // It is written as a big endian 32 bit number
-    uint32_t main_db_page = ReadBE32(UCharCast(std::get<DataRecord>(page.records.at(1)).data.data()));
+    uint32_t main_db_page = ReadBE32(std::get<DataRecord>(page.records.at(1)).data.data());
 
     // The main database is in a page that doesn't exist
     if (main_db_page > outer_meta.last_page) {