diff --git a/include/rapidjson/internal/ieee754.h b/include/rapidjson/internal/ieee754.h
index 0b9393e..152be8f 100644
--- a/include/rapidjson/internal/ieee754.h
+++ b/include/rapidjson/internal/ieee754.h
@@ -36,7 +36,7 @@ public:
 
     double PreviousPositiveDouble() const {
         RAPIDJSON_ASSERT(!Sign());
-        if (d == 0.0)
+        if (IsZero())
             return 0.0;
         else
             return Double(u - 1).Value();
diff --git a/include/rapidjson/reader.h b/include/rapidjson/reader.h
index 0ee2523..d9da869 100644
--- a/include/rapidjson/reader.h
+++ b/include/rapidjson/reader.h
@@ -896,7 +896,7 @@ private:
                 if (significandDigit < 17) {
                     d = d * 10.0 + (s.TakePush() - '0');
                     --expFrac;
-                    if (d != 0.0)
+                    if (d > 0.0)
                         significandDigit++;
                 }
                 else