diff --git a/ChangeLog b/ChangeLog
index 53d9caf8..dba05ebc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -20,6 +20,8 @@ brevity.  Much more detail can be found in the git revision history:
     specify the old chunk size rather than the new chunk size.  This bug caused
     no correctness issues for the default chunk purge function, but was
     visible to custom functions set via the "arena.<i>.chunk_hooks" mallctl.
+  - Fix TLS configuration such that it is enabled by default for platforms on
+    which it works correctly.
 
 * 4.0.0 (August 17, 2015)
 
diff --git a/configure.ac b/configure.ac
index f7c7f3ce..5e77b680 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1272,13 +1272,16 @@ fi
 ,
 enable_tls=""
 )
-if test "x${enable_tls}" = "x" -a "x${force_tls}" = "x1" ; then
-  AC_MSG_RESULT([Forcing TLS to avoid allocator/threading bootstrap issues])
-  enable_tls="1"
-fi
-if test "x${enable_tls}" = "x" -a "x${force_tls}" = "x0" ; then
-  AC_MSG_RESULT([Forcing no TLS to avoid allocator/threading bootstrap issues])
-  enable_tls="0"
+if test "x${enable_tls}" = "x" ; then
+  if test "x${force_tls}" = "x1" ; then
+    AC_MSG_RESULT([Forcing TLS to avoid allocator/threading bootstrap issues])
+    enable_tls="1"
+  elif test "x${force_tls}" = "x0" ; then
+    AC_MSG_RESULT([Forcing no TLS to avoid allocator/threading bootstrap issues])
+    enable_tls="0"
+  else
+    enable_tls="1"
+  fi
 fi
 if test "x${enable_tls}" = "x1" ; then
 AC_MSG_CHECKING([for TLS])
@@ -1298,9 +1301,12 @@ else
 fi
 AC_SUBST([enable_tls])
 if test "x${enable_tls}" = "x1" ; then
+  if test "x${force_tls}" = "x0" ; then
+    AC_MSG_WARN([TLS enabled despite being marked unusable on this platform])
+  fi
   AC_DEFINE_UNQUOTED([JEMALLOC_TLS], [ ])
 elif test "x${force_tls}" = "x1" ; then
-  AC_MSG_ERROR([Failed to configure TLS, which is mandatory for correct function])
+  AC_MSG_WARN([TLS disabled despite being marked critical on this platform])
 fi
 
 dnl ============================================================================