diff --git a/string/strerror_l.c b/string/strerror_l.c
index 15cce261e6..70456e5bb4 100644
--- a/string/strerror_l.c
+++ b/string/strerror_l.c
@@ -20,7 +20,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <tls-internal.h>
-
+#include <libc-internal.h>
 
 static const char *
 translate (const char *str, locale_t loc)
@@ -31,6 +31,12 @@ translate (const char *str, locale_t loc)
   return res;
 }
 
+static char *
+unknown_error (locale_t loc)
+{
+  return (char *) translate ("Unknown error", loc);
+}
+
 
 /* Return a string describing the errno code in ERRNUM.  */
 char *
@@ -40,18 +46,25 @@ __strerror_l (int errnum, locale_t loc)
   char *err = (char *) __get_errlist (errnum);
   if (__glibc_unlikely (err == NULL))
     {
-      struct tls_internal_t *tls_internal = __glibc_tls_internal ();
-      free (tls_internal->strerror_l_buf);
-      if (__asprintf (&tls_internal->strerror_l_buf, "%s%d",
-		      translate ("Unknown error ", loc), errnum) > 0)
-	err = tls_internal->strerror_l_buf;
-      else
+      if (__libc_initial)
 	{
-	  /* The memory was freed above.  */
-	  tls_internal->strerror_l_buf = NULL;
-	  /* Provide a fallback translation.  */
-	  err = (char *) translate ("Unknown error", loc);
+	  struct tls_internal_t *tls_internal = __glibc_tls_internal ();
+	  free (tls_internal->strerror_l_buf);
+	  if (__asprintf (&tls_internal->strerror_l_buf, "%s%d",
+			  translate ("Unknown error ", loc), errnum) > 0)
+	    err = tls_internal->strerror_l_buf;
+	  else
+	    {
+	      /* The memory was freed above.  */
+	      tls_internal->strerror_l_buf = NULL;
+	      /* Provide a fallback translation.  */
+	      err = unknown_error (loc);
+	    }
 	}
+      else
+	/* Secondary namespaces use a different malloc, so cannot
+	   participate in the buffer management.  */
+	err = unknown_error (loc);
     }
   else
     err = (char *) translate (err, loc);
diff --git a/string/strsignal.c b/string/strsignal.c
index 3114601564..d9b0365468 100644
--- a/string/strsignal.c
+++ b/string/strsignal.c
@@ -21,6 +21,7 @@
 #include <string.h>
 #include <libintl.h>
 #include <tls-internal.h>
+#include <libc-internal.h>
 
 /* Return a string describing the meaning of the signal number SIGNUM.  */
 char *
@@ -30,21 +31,28 @@ strsignal (int signum)
   if (desc != NULL)
     return _(desc);
 
-  struct tls_internal_t *tls_internal = __glibc_tls_internal ();
-  free (tls_internal->strsignal_buf);
+  if (__libc_initial)
+    {
+      struct tls_internal_t *tls_internal = __glibc_tls_internal ();
+      free (tls_internal->strsignal_buf);
 
-  int r;
+      int r;
 #ifdef SIGRTMIN
-  if (signum >= SIGRTMIN && signum <= SIGRTMAX)
-    r = __asprintf (&tls_internal->strsignal_buf, _("Real-time signal %d"),
-		    signum - SIGRTMIN);
-  else
+      if (signum >= SIGRTMIN && signum <= SIGRTMAX)
+	r = __asprintf (&tls_internal->strsignal_buf, _("Real-time signal %d"),
+			signum - SIGRTMIN);
+      else
 #endif
-    r = __asprintf (&tls_internal->strsignal_buf, _("Unknown signal %d"),
-		    signum);
+	r = __asprintf (&tls_internal->strsignal_buf, _("Unknown signal %d"),
+			signum);
 
-  if (r == -1)
-    tls_internal->strsignal_buf = NULL;
-
-  return tls_internal->strsignal_buf;
+      if (r >= 0)
+	return tls_internal->strsignal_buf;
+      else
+	tls_internal->strsignal_buf = NULL;
+    }
+  /* Fall through on asprintf error, and for !__libc_initial:
+     secondary namespaces use a different malloc and cannot
+     participate in the buffer management.  */
+  return _("Unknown signal");
 }