diff --git a/libwvdrmengine/cdm/util/src/string_conversions.cpp b/libwvdrmengine/cdm/util/src/string_conversions.cpp
index 9e822102..f3a0ba4d 100644
--- a/libwvdrmengine/cdm/util/src/string_conversions.cpp
+++ b/libwvdrmengine/cdm/util/src/string_conversions.cpp
@@ -33,9 +33,11 @@ const char kBase64SafeCodes[] =
 // Decodes a single Base64 encoded character into its 6-bit value.
 // The provided |codes| must be a Base64 character map.
 int DecodeBase64Char(char c, const char* codes) {
-  const char* it = strchr(codes, c);
-  if (it == nullptr) return -1;
-  return it - codes;
+  const char* c_in_codes = strchr(codes, c);
+  if (c_in_codes == nullptr) return -1;
+  const uintptr_t c_in_codes_int = reinterpret_cast<uintptr_t>(c_in_codes);
+  const uintptr_t codes_int = reinterpret_cast<uintptr_t>(codes);
+  return static_cast<int>(c_in_codes_int - codes_int);
 }
 
 bool DecodeHexChar(char ch, uint8_t* digit) {
@@ -158,9 +160,9 @@ std::vector<uint8_t> Base64DecodeInternal(const char* encoded, size_t length,
 // converts an ascii hex string(2 bytes per digit) into a decimal byte string
 std::vector<uint8_t> a2b_hex(const std::string& byte) {
   std::vector<uint8_t> array;
-  unsigned int count = byte.size();
+  size_t count = byte.size();
   if (count == 0 || (count % 2) != 0) {
-    LOGE("Invalid input size %u for string %s", count, byte.c_str());
+    LOGE("Invalid input size %zu for string %s", count, byte.c_str());
     return array;
   }