diff --git a/c++/src/H5Attribute.cpp b/c++/src/H5Attribute.cpp
index 520a4f6ea9..a0aa33fdca 100644
--- a/c++/src/H5Attribute.cpp
+++ b/c++/src/H5Attribute.cpp
@@ -11,6 +11,7 @@
  * help@hdfgroup.org.                                                        *
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
+#include <cstdlib>
 #include <iostream>
 #include <string>
 
diff --git a/c++/src/H5DataSet.cpp b/c++/src/H5DataSet.cpp
index 627d81bb01..68ddefa379 100644
--- a/c++/src/H5DataSet.cpp
+++ b/c++/src/H5DataSet.cpp
@@ -11,6 +11,7 @@
  * help@hdfgroup.org.                                                        *
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
+#include <cstdlib>
 #include <iostream>
 #include <string>
 
diff --git a/c++/src/H5DataType.cpp b/c++/src/H5DataType.cpp
index ff8f6dcf62..d889f135c9 100644
--- a/c++/src/H5DataType.cpp
+++ b/c++/src/H5DataType.cpp
@@ -11,6 +11,7 @@
  * help@hdfgroup.org.                                                        *
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
+#include <cstdlib>
 #include <iostream>
 #include <string>
 
diff --git a/c++/src/H5FaccProp.cpp b/c++/src/H5FaccProp.cpp
index 1edf4ad5a2..68a130eac0 100644
--- a/c++/src/H5FaccProp.cpp
+++ b/c++/src/H5FaccProp.cpp
@@ -17,8 +17,6 @@
 using std::cerr;
 using std::endl;
 
-//#include <string>
-
 #include "H5Include.h"
 #include "H5Exception.h"
 #include "H5IdComponent.h"
diff --git a/c++/src/H5Library.cpp b/c++/src/H5Library.cpp
index 37516be9f4..19c7ee78a7 100644
--- a/c++/src/H5Library.cpp
+++ b/c++/src/H5Library.cpp
@@ -11,8 +11,8 @@
  * help@hdfgroup.org.                                                        *
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
-#include <string>
 #include <cstdlib>
+#include <string>
 
 #include "H5CppDoc.h" // included only for Doxygen to generate part of RM
 #include "H5Include.h"
diff --git a/c++/src/H5Location.cpp b/c++/src/H5Location.cpp
index 13a89aa7e2..915f2a9676 100644
--- a/c++/src/H5Location.cpp
+++ b/c++/src/H5Location.cpp
@@ -11,8 +11,8 @@
  * help@hdfgroup.org.                                                        *
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
-#include <string>
 #include <iostream>
+#include <string>
 using namespace std;
 
 #include "H5Include.h"
diff --git a/c++/src/H5PropList.cpp b/c++/src/H5PropList.cpp
index e7a83af88f..d4e7b397d4 100644
--- a/c++/src/H5PropList.cpp
+++ b/c++/src/H5PropList.cpp
@@ -12,7 +12,6 @@
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 #include <iostream>
-
 #include <string>
 
 #include "H5Include.h"
diff --git a/c++/test/dsets.cpp b/c++/test/dsets.cpp
index 53b56fc6bc..55ffd67740 100644
--- a/c++/test/dsets.cpp
+++ b/c++/test/dsets.cpp
@@ -412,7 +412,6 @@ const H5Z_class2_t H5Z_BOGUS[1] = {{
 static size_t
 filter_bogus(unsigned int flags, size_t cd_nelmts, const unsigned int cd_values[], size_t nbytes,
              size_t *buf_size, void **buf)
-// H5_ATTR_UNUSED variables caused warning, but taking them out caused failure.
 {
     // Unused
     (void)flags;