diff --git a/include/json/config.h b/include/json/config.h
index 7f9ac69..ad55a4d 100644
--- a/include/json/config.h
+++ b/include/json/config.h
@@ -80,8 +80,8 @@ extern JSON_API int msvc_pre1900_c99_snprintf(char* outBuf, size_t size,
 // These Macros are maintained for backwards compatibility of external tools.
 #if (defined(_MSC_VER) && _MSC_VER >= 1900) ||                                 \
     (defined(__GNUC__) && __cplusplus >= 201103L) ||                           \
-    (defined(__clang__) && __clang_major__ == 3 && __clang_minor__ >= 3)
 
+    (defined(__clang__) && (__clang_major__ > 3 || (__clang_major__ == 3 && __clang_minor__ >= 3)))
 #define JSONCPP_CXX_STD_11 1
 #else
 #define JSONCPP_CXX_STD_11 0
diff --git a/src/lib_json/json_value.cpp b/src/lib_json/json_value.cpp
index 2938ea5..f0326e6 100644
--- a/src/lib_json/json_value.cpp
+++ b/src/lib_json/json_value.cpp
@@ -1251,7 +1251,7 @@ Value::Members Value::getMemberNames() const {
 
 static bool IsIntegral(double d) {
   double integral_part;
-  return modf(d, &integral_part) == 0.0;
+  return std::modf(d, &integral_part) == 0.0;
 }
 
 bool Value::isNull() const { return type() == nullValue; }