diff --git a/src/tup/entry.c b/src/tup/entry.c
index 16d61fe8..90bc2c96 100644
--- a/src/tup/entry.c
+++ b/src/tup/entry.c
@@ -359,7 +359,19 @@ static int entry_openat_internal(int root_dfd, struct tup_entry *tent)
 	if(!tent)
 		return -1;
 	if(tent->parent == NULL) {
-		return fcntl(root_dfd, F_DUPFD_CLOEXEC, 0);
+#ifdef F_DUPFD_CLOEXEC
+		int fd = fcntl(root_dfd, F_DUPFD_CLOEXEC, 0);
+		if(fd != -1 || errno != EINVAL)
+			return fd;
+#endif
+		int fd = fcntl(root_dfd, F_DUPFD, 0);
+		if(fd == -1)
+			return -1;
+		if(fcntl(fd, F_SETFD, FD_CLOEXEC) == -1) {
+			close(fd);
+			return -1;
+		}
+		return fd;
 	}
 
 	dfd = entry_openat_internal(root_dfd, tent->parent);
diff --git a/src/tup/platform.c b/src/tup/platform.c
index 3ccc47cd..6e24f6d8 100644
--- a/src/tup/platform.c
+++ b/src/tup/platform.c
@@ -44,9 +44,9 @@ const char *tup_platform = "netbsd";
 const char *tup_arch = "x86_64";
 #elif __i386__
 const char *tup_arch = "i386";
-#elif __powerpc__
+#elif __powerpc__ || __ppc__
 const char *tup_arch = "powerpc";
-#elif __powerpc64__
+#elif __powerpc64__ || __ppc64__
 const char *tup_arch = "powerpc64";
 #elif __ia64__
 const char *tup_arch = "ia64";