diff --git a/include/xgboost/base.h b/include/xgboost/base.h
index 78c46e5ac..0e3fbd981 100644
--- a/include/xgboost/base.h
+++ b/include/xgboost/base.h
@@ -55,7 +55,7 @@
 #endif  // defined(__GNUC__) && ((__GNUC__ == 4 && __GNUC_MINOR__ >= 8) || __GNUC__ > 4)
 
 #if defined(__GNUC__) && ((__GNUC__ == 4 && __GNUC_MINOR__ >= 8) || __GNUC__ > 4) && \
-    !defined(__CUDACC__)
+    !defined(__CUDACC__) && !defined(__sun) && !defined(sun)
 #include <parallel/algorithm>
 #define XGBOOST_PARALLEL_SORT(X, Y, Z) __gnu_parallel::sort((X), (Y), (Z))
 #define XGBOOST_PARALLEL_STABLE_SORT(X, Y, Z) \
diff --git a/rabit/include/rabit/internal/socket.h b/rabit/include/rabit/internal/socket.h
index 2e10cf50c..b4d77e15c 100644
--- a/rabit/include/rabit/internal/socket.h
+++ b/rabit/include/rabit/internal/socket.h
@@ -25,6 +25,10 @@
 #include <sys/socket.h>
 #include <sys/ioctl.h>
 
+#if defined(__sun) || defined(sun)
+#include <sys/sockio.h>
+#endif  // defined(__sun) || defined(sun)
+
 #endif  // defined(_WIN32)
 
 #include <string>