diff --git a/src/base/net/stratum/Client.cpp b/src/base/net/stratum/Client.cpp
index 039ff6930..7b9c32229 100644
--- a/src/base/net/stratum/Client.cpp
+++ b/src/base/net/stratum/Client.cpp
@@ -445,9 +445,9 @@ bool xmrig::Client::parseJob(const rapidjson::Value &params, int *code)
     if (Cvt::fromHex(signatureKeyBuf, sizeof(signatureKeyBuf), Json::getValue(params, "sig_key"))) {
         job.setEphemeralKeys(signatureKeyBuf, signatureKeyBuf + 32);
 
-        uint8_t major_version;
-        uint8_t minor_version;
-        uint64_t timestamp;
+        uint8_t major_version = 0;
+        uint8_t minor_version = 0;
+        uint64_t timestamp = 0;
 
         CBlobReader ar(job.blob(), job.size());
         ar(major_version);
diff --git a/src/base/tools/cryptonote/WalletAddress.cpp b/src/base/tools/cryptonote/WalletAddress.cpp
index 394274daa..7be1ef9d6 100644
--- a/src/base/tools/cryptonote/WalletAddress.cpp
+++ b/src/base/tools/cryptonote/WalletAddress.cpp
@@ -39,8 +39,8 @@ bool WalletAddress::Decode(const String& address)
     int8_t reverse_alphabet[256];
     memset(reverse_alphabet, -1, sizeof(reverse_alphabet));
 
-    for (int i = 0; i < alphabet_size; ++i) {
-        reverse_alphabet[alphabet[i]] = i;
+    for (size_t i = 0; i < alphabet_size; ++i) {
+        reverse_alphabet[static_cast<int>(alphabet[i])] = i;
     }
 
     const int len = static_cast<int>(address.size());
@@ -49,7 +49,7 @@ bool WalletAddress::Decode(const String& address)
 
     int last_block_size_index = -1;
 
-    for (int i = 0; i < block_sizes.size(); ++i) {
+    for (size_t i = 0; i < block_sizes.size(); ++i) {
         if (block_sizes[i] == last_block_size) {
             last_block_size_index = i;
             break;
@@ -70,7 +70,7 @@ bool WalletAddress::Decode(const String& address)
         uint64_t order = 1;
 
         for (int j = ((i < num_full_blocks) ? block_sizes.back() : last_block_size) - 1; j >= 0; --j) {
-            const int digit = reverse_alphabet[address_data[j]];
+            const int digit = reverse_alphabet[static_cast<int>(address_data[j])];
             if (digit < 0) {
                 return false;
             }
diff --git a/src/hw/dmi/DmiReader_win.cpp b/src/hw/dmi/DmiReader_win.cpp
index 837bdb7b3..26f8a7f61 100644
--- a/src/hw/dmi/DmiReader_win.cpp
+++ b/src/hw/dmi/DmiReader_win.cpp
@@ -46,14 +46,16 @@ struct RawSMBIOSData {
 
 bool xmrig::DmiReader::read()
 {
-    const uint32_t size = GetSystemFirmwareTable('RSMB', 0, nullptr, 0);
+    constexpr uint32_t RSMB = 0x52534D42;
+
+    const uint32_t size = GetSystemFirmwareTable(RSMB, 0, nullptr, 0);
     auto smb            = reinterpret_cast<RawSMBIOSData *>(HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, size));
 
     if (!smb) {
         return false;
     }
 
-    if (GetSystemFirmwareTable('RSMB', 0, smb, size) != size) {
+    if (GetSystemFirmwareTable(RSMB, 0, smb, size) != size) {
         HeapFree(GetProcessHeap(), 0, smb);
 
         return false;