diff --git a/tests/ls/getxattr-speedup b/tests/ls/getxattr-speedup
index f3dc5bb..9127a28 100755
--- a/tests/ls/getxattr-speedup
+++ b/tests/ls/getxattr-speedup
@@ -21,7 +21,8 @@
 . "${srcdir=.}/init.sh"; path_prepend_ ../src
 print_ver_ ls
 
-fd=33
+speeduptext="__SPEEDUP__"
+speeduptextlen=$( echo "$speeduptext" | wc -c )  # also count newline.
 
 # Replace each getxattr and lgetxattr call with a call to these stubs.
 # Each writes a single line to the specified FD so that we can later
@@ -32,29 +33,27 @@ cat > k.c <<'EOF' || framework_failure_
 static void
 write_1 (void)
 {
-  int fd = @FD@;
-  write (fd, "x\n", 2);
+  write (1, SPEEDUPTEXT "\n", SPEEDUPTEXTLEN);
 }
 ssize_t getxattr (const char *path, const char *name, void *value, size_t size)
 { write_1 (); errno = ENOTSUP; return -1; }
 ssize_t lgetxattr(const char *path, const char *name, void *value, size_t size)
 { write_1 (); errno = ENOTSUP; return -1; }
 EOF
-sed "s/@FD@/$fd/" k.c > k || framework_failure_
-mv k k.c || framework_failure_
 
 # Then compile/link it:
-$CC -fPIC -O2 -c k.c || framework_failure_ 'failed to compile with -fPIC'
+$CC -DSPEEDUPTEXT="\"$speeduptext\"" -DSPEEDUPTEXTLEN="$speeduptextlen" \
+  -fPIC -O2 -c k.c || framework_failure_ 'failed to compile with -fPIC'
 ld -G k.o -o k.so || framework_failure_ 'failed to invoke ld -G ...'
 
 # create a few files
 seq 100 | xargs touch || framework_failure_
 
 # Finally, run the test, redirecting
-eval "LD_PRELOAD=$PWD/k.so ls --color=always -l . $fd>x" || fail=1
+eval "LD_PRELOAD=$PWD/k.so ls --color=always -l . >x" || fail=1
 
 # Ensure that there were no more than 3 *getxattr calls.
-n_calls=$(wc -l < x)
+n_calls=$( grep "^$speeduptext\$" x | wc -l)
 test "$n_calls" -le 3 || fail=1
 
 Exit $fail