diff --git a/MANIFEST b/MANIFEST
index 25d4b4fc0..632a2b1bd 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -43,6 +43,7 @@ compat/regress/fnmatch/fnm_test.in
 compat/regress/glob/files
 compat/regress/glob/globtest.c
 compat/regress/glob/globtest.in
+compat/stdbool.h
 compat/setenv.c
 compat/siglist.in
 compat/snprintf.c
diff --git a/compat/stdbool.h b/compat/stdbool.h
index bd06a1db3..3771cfef3 100644
--- a/compat/stdbool.h
+++ b/compat/stdbool.h
@@ -10,7 +10,7 @@
 
 #ifndef __cplusplus
 
-#if (defined(__GNUC__) && __GNUC__ >= 3) || defined(__PCC__) || defined(lint)
+#if (defined(__GNUC__) && __GNUC__ >= 3) || (defined(__SUNPRO_C) && __SUNPRO_C >= 0x550) || defined(__PCC__) || defined(lint)
 /* Support for _C99: type _Bool is already built-in. */
 #define false	0
 #define true	1