diff --git a/libs/spandsp/src/at_interpreter.c b/libs/spandsp/src/at_interpreter.c
index 5d488a2685..602a737223 100644
--- a/libs/spandsp/src/at_interpreter.c
+++ b/libs/spandsp/src/at_interpreter.c
@@ -34,6 +34,10 @@
 #include "config.h"
 #endif
 
+#if defined(__sun)
+#define __EXTENSIONS__
+#endif
+
 #include <inttypes.h>
 #include <stdlib.h>
 #include <stdio.h>