diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 09ba9bff2..23489ca1f 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,8 @@
+2010-01-29  Corinna Vinschen  <corinna@vinschen.de>
+
+	* libc/strfmon.c (__setup_vars): Test for an empty string rather than
+	for a NULL pointer.
+
 2010-01-29  Christopher Faylor  <me+cygwin@cgf.cx>
 
 	* dll_init.cc (remove_dll_atexit): New function.
diff --git a/winsup/cygwin/libc/strfmon.c b/winsup/cygwin/libc/strfmon.c
index ac23aa05b..79f8ab461 100644
--- a/winsup/cygwin/libc/strfmon.c
+++ b/winsup/cygwin/libc/strfmon.c
@@ -419,7 +419,7 @@ __setup_vars(int flags, char *cs_precedes, char *sep_by_space,
 		*cs_precedes = lc->int_n_cs_precedes;
 		*sep_by_space = lc->int_n_sep_by_space;
 		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->int_n_sign_posn;
-		*signstr = (lc->negative_sign == NULL) ? negative
+		*signstr = (*lc->negative_sign == '\0') ? negative
 		    : lc->negative_sign;
 	} else if (flags & USE_INTL_CURRENCY) {
 		*cs_precedes = lc->int_p_cs_precedes;
@@ -430,7 +430,7 @@ __setup_vars(int flags, char *cs_precedes, char *sep_by_space,
 		*cs_precedes = lc->n_cs_precedes;
 		*sep_by_space = lc->n_sep_by_space;
 		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->n_sign_posn;
-		*signstr = (lc->negative_sign == NULL) ? negative
+		*signstr = (*lc->negative_sign == '\0') ? negative
 		    : lc->negative_sign;
 	} else {
 		*cs_precedes = lc->p_cs_precedes;