diff --git a/include/rapidjson/internal/biginteger.h b/include/rapidjson/internal/biginteger.h
index 5baba9b..99a30ac 100755
--- a/include/rapidjson/internal/biginteger.h
+++ b/include/rapidjson/internal/biginteger.h
@@ -97,7 +97,7 @@ public:
         if (u == 1) return *this;
         if (*this == 1) return *this = u;
 
-        uint32_t k = 0;
+        uint64_t k = 0;
         for (size_t i = 0; i < count_; i++) {
             const uint64_t c = digits_[i] >> 32;
             const uint64_t d = digits_[i] & 0xFFFFFFFF;
@@ -246,7 +246,7 @@ private:
         __extension__ typedef unsigned __int128 uint128;
         uint128 p = static_cast<uint128>(a) * static_cast<uint128>(b);
         p += k;
-        *outHigh = p >> 64;
+        *outHigh = static_cast<uint64_t>(p >> 64);
         return static_cast<uint64_t>(p);
 #else
         const uint64_t a0 = a & 0xFFFFFFFF, a1 = a >> 32, b0 = b & 0xFFFFFFFF, b1 = b >> 32;
diff --git a/include/rapidjson/internal/diyfp.h b/include/rapidjson/internal/diyfp.h
index 4ef53d9..3b6c423 100644
--- a/include/rapidjson/internal/diyfp.h
+++ b/include/rapidjson/internal/diyfp.h
@@ -45,7 +45,7 @@ struct DiyFp {
             uint64_t u64;
         } u = { d };
 
-        int biased_e = (u.u64 & kDpExponentMask) >> kDpSignificandSize;
+        int biased_e = static_cast<int>((u.u64 & kDpExponentMask) >> kDpSignificandSize);
         uint64_t significand = (u.u64 & kDpSignificandMask);
         if (biased_e != 0) {
             f = significand + kDpHiddenBit;
@@ -71,7 +71,7 @@ struct DiyFp {
 #elif (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)) && defined(__x86_64__)
         __extension__ typedef unsigned __int128 uint128;
         uint128 p = static_cast<uint128>(f) * static_cast<uint128>(rhs.f);
-        uint64_t h = p >> 64;
+        uint64_t h = static_cast<uint64_t>(p >> 64);
         uint64_t l = static_cast<uint64_t>(p);
         if (l & (uint64_t(1) << 63)) // rounding
             h++;
diff --git a/include/rapidjson/internal/ieee754.h b/include/rapidjson/internal/ieee754.h
index 9a82880..e3f0336 100644
--- a/include/rapidjson/internal/ieee754.h
+++ b/include/rapidjson/internal/ieee754.h
@@ -23,29 +23,29 @@ namespace internal {
 class Double {
 public:
     Double() {}
-    Double(double d) : d(d) {}
-    Double(uint64_t u) : u(u) {}
+    Double(double d) : d_(d) {}
+    Double(uint64_t u) : u_(u) {}
 
-    double Value() const { return d; }
-    uint64_t Uint64Value() const { return u; }
+    double Value() const { return d_; }
+    uint64_t Uint64Value() const { return u_; }
 
     double NextPositiveDouble() const {
         RAPIDJSON_ASSERT(!Sign());
-        return Double(u + 1).Value();
+        return Double(u_ + 1).Value();
     }
 
-    bool Sign() const { return (u & kSignMask) != 0; }
-    uint64_t Significand() const { return u & kSignificandMask; }
-    int Exponent() const { return ((u & kExponentMask) >> kSignificandSize) - kExponentBias; }
+    bool Sign() const { return (u_ & kSignMask) != 0; }
+    uint64_t Significand() const { return u_ & kSignificandMask; }
+    int Exponent() const { return static_cast<int>(((u_ & kExponentMask) >> kSignificandSize) - kExponentBias); }
 
-    bool IsNan() const { return (u & kExponentMask) == kExponentMask && Significand() != 0; }
-    bool IsInf() const { return (u & kExponentMask) == kExponentMask && Significand() == 0; }
-    bool IsNormal() const { return (u & kExponentMask) != 0 || Significand() == 0; }
-    bool IsZero() const { return (u & (kExponentMask | kSignificandMask)) == 0; }
+    bool IsNan() const { return (u_ & kExponentMask) == kExponentMask && Significand() != 0; }
+    bool IsInf() const { return (u_ & kExponentMask) == kExponentMask && Significand() == 0; }
+    bool IsNormal() const { return (u_ & kExponentMask) != 0 || Significand() == 0; }
+    bool IsZero() const { return (u_ & (kExponentMask | kSignificandMask)) == 0; }
 
     uint64_t IntegerSignificand() const { return IsNormal() ? Significand() | kHiddenBit : Significand(); }
     int IntegerExponent() const { return (IsNormal() ? Exponent() : kDenormalExponent) - kSignificandSize; }
-    uint64_t ToBias() const { return (u & kSignMask) ? ~u + 1 : u | kSignMask; }
+    uint64_t ToBias() const { return (u_ & kSignMask) ? ~u_ + 1 : u_ | kSignMask; }
 
     static unsigned EffectiveSignificandSize(int order) {
         if (order >= -1021)
@@ -66,8 +66,8 @@ private:
     static const uint64_t kHiddenBit = RAPIDJSON_UINT64_C2(0x00100000, 0x00000000);
 
     union {
-        double d;
-        uint64_t u;
+        double d_;
+        uint64_t u_;
     };
 };