diff --git a/src/backend/distributed/shared_library_init.c b/src/backend/distributed/shared_library_init.c
index 2a02b6783..2235bf5f2 100644
--- a/src/backend/distributed/shared_library_init.c
+++ b/src/backend/distributed/shared_library_init.c
@@ -13,6 +13,11 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 
+/* necessary to get alloca() on illumos */
+#ifdef __sun
+#include <alloca.h>
+#endif
+
 #include "fmgr.h"
 #include "miscadmin.h"
 
diff --git a/src/backend/distributed/worker/worker_sql_task_protocol.c b/src/backend/distributed/worker/worker_sql_task_protocol.c
index 7d441b8fe..9ccd5a9a5 100644
--- a/src/backend/distributed/worker/worker_sql_task_protocol.c
+++ b/src/backend/distributed/worker/worker_sql_task_protocol.c
@@ -21,6 +21,8 @@
 #include "utils/builtins.h"
 #include "utils/memutils.h"
 
+/* necessary to get S_IRUSR, S_IWUSR definitions on illumos */
+#include <sys/stat.h>
 
 /* TaskFileDestReceiver can be used to stream results into a file */
 typedef struct TaskFileDestReceiver