diff --git a/lib/libc/stdlib/strfmon.c b/lib/libc/stdlib/strfmon.c
--- a/lib/libc/stdlib/strfmon.c
+++ b/lib/libc/stdlib/strfmon.c
@@ -457,7 +457,7 @@
 	if (*sep_by_space == CHAR_MAX)
 		*sep_by_space = 0;
 	if (*sign_posn == CHAR_MAX)
-		*sign_posn = 0;
+		*sign_posn = 1;
 }
 
 static int
diff --git a/lib/libc/tests/stdlib/strfmon_test.c b/lib/libc/tests/stdlib/strfmon_test.c
--- a/lib/libc/tests/stdlib/strfmon_test.c
+++ b/lib/libc/tests/stdlib/strfmon_test.c
@@ -205,8 +205,8 @@
 	    { "%(i", "C", "[123.45] [(123.45)]" },
 	    { "%(n", "en_US.UTF-8", "[$123.45] [($123.45)]" },
 	    { "%(i", "en_US.UTF-8", "[USD123.45] [(USD123.45)]" },
-	    { "%n", "C", "[123.45] [(123.45)]" }, /* XXX */
-	    { "%i", "C", "[123.45] [(123.45)]" }, /* XXX */
+	    { "%n", "C", "[123.45] [-123.45]" },
+	    { "%i", "C", "[123.45] [-123.45]" },
 	    { "%n", "en_US.UTF-8", "[$123.45] [-$123.45]" },
 	    { "%i", "en_US.UTF-8", "[USD123.45] [-USD123.45]" },
 	};
@@ -253,7 +253,7 @@
 		const char *locale;
 		const char *expected;
 	} tests[] = {
-	    { "C", "[ **1234.57 ] [ **1234.57 ]" }, /* XXX */
+	    { "C", "[ **1234.57] [ **1234.57]" },
 	    { "de_DE.UTF-8", "[ **1234,57 €] [ **1.234,57 EUR]" },
 	    { "en_GB.UTF-8", "[ £**1234.57] [ GBP**1,234.57]" },
 	};