diff --git a/src/CHANGELOG b/src/CHANGELOG
index ed438ba7c..45a16548d 100644
--- a/src/CHANGELOG
+++ b/src/CHANGELOG
@@ -74,6 +74,9 @@ ECL 8.9.0:
    names while keeping the old definitions as macros. Look at external.h for
    the list of already deprecated names.
 
+ - ECL builds using thread local storage when configured with --with-__thread and
+   the feature works on that platform.
+
 * Embedding:
 
  - ECL now implements a more transparent interface for setting and querying
diff --git a/src/aclocal.m4 b/src/aclocal.m4
index 9b117e5db..d7c9f1373 100644
--- a/src/aclocal.m4
+++ b/src/aclocal.m4
@@ -600,7 +600,6 @@ AC_TRY_COMPILE(,[static __thread void *data;],
    ac_cv_ecl___thread=yes,
    ac_cv_ecl___thread=no))
 dnl We deactivate this test because it seems to slow down ECL A LOT!!!
-ac_cv_ecl___thread=no
 ])
 
 dnl ----------------------------------------------------------------------
diff --git a/src/c/threads.d b/src/c/threads.d
index 5da7f6477..aa9f6149a 100644
--- a/src/c/threads.d
+++ b/src/c/threads.d
@@ -76,7 +76,7 @@ ecl_process_env(void)
 static void
 ecl_set_process_env(cl_env_ptr env)
 {
-#ifdef WITH__THREAD
+#ifdef WITH___THREAD
 	cl_env_p = env;
 #else
 # ifdef ECL_WINDOWS_THREADS
@@ -651,7 +651,7 @@ init_threads(cl_env_ptr env)
 	process->process.env = env;
 
 	env->own_process = process;
-#if !defined(WITH__THREADS)
+#if !defined(WITH___THREAD)
 # if defined(ECL_WINDOWS_THREADS)
 	cl_env_key = TlsAlloc();
 # else
diff --git a/src/configure b/src/configure
index 57ff33c2f..1a15e8990 100755
--- a/src/configure
+++ b/src/configure
@@ -4545,7 +4545,6 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
 fi
 { $as_echo "$as_me:$LINENO: result: $ac_cv_ecl___thread" >&5
 $as_echo "$ac_cv_ecl___thread" >&6; }
-ac_cv_ecl___thread=no