diff --git a/bison.simple b/bison.simple
index 555df94a..88fad589 100644
--- a/bison.simple
+++ b/bison.simple
@@ -32,7 +32,7 @@
 #ifdef __GNUC__
 #define alloca __builtin_alloca
 #else /* not GNU C.  */
-#if (!defined (__STDC__) && defined (sparc)) || defined (__sparc__) || defined (__sparc) || defined (__sgi)
+#if (!defined (__STDC__) && defined (sparc)) || defined (__sparc__) || defined (__sparc) || defined (__sgi) || (defined (__sun) && defined (__i386))
 #include <alloca.h>
 #else /* not sparc */
 /* This used to test MSDOS, but that is a bad idea
diff --git a/src/bison.s1 b/src/bison.s1
index 555df94a..88fad589 100644
--- a/src/bison.s1
+++ b/src/bison.s1
@@ -32,7 +32,7 @@
 #ifdef __GNUC__
 #define alloca __builtin_alloca
 #else /* not GNU C.  */
-#if (!defined (__STDC__) && defined (sparc)) || defined (__sparc__) || defined (__sparc) || defined (__sgi)
+#if (!defined (__STDC__) && defined (sparc)) || defined (__sparc__) || defined (__sparc) || defined (__sgi) || (defined (__sun) && defined (__i386))
 #include <alloca.h>
 #else /* not sparc */
 /* This used to test MSDOS, but that is a bad idea
diff --git a/src/bison.simple b/src/bison.simple
index 555df94a..88fad589 100644
--- a/src/bison.simple
+++ b/src/bison.simple
@@ -32,7 +32,7 @@
 #ifdef __GNUC__
 #define alloca __builtin_alloca
 #else /* not GNU C.  */
-#if (!defined (__STDC__) && defined (sparc)) || defined (__sparc__) || defined (__sparc) || defined (__sgi)
+#if (!defined (__STDC__) && defined (sparc)) || defined (__sparc__) || defined (__sparc) || defined (__sgi) || (defined (__sun) && defined (__i386))
 #include <alloca.h>
 #else /* not sparc */
 /* This used to test MSDOS, but that is a bad idea