diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index efc8bdd5b85..50a9cf75376 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2016-12-12  Jakub Jelinek  <jakub@redhat.com>
+
+	PR other/78766
+	* opt-functions.awk (opt_args): Use [{] instead of { in regexps.
+	Formatting fix.
+
 2016-12-12  Martin Sebor  <msebor@redhat.com>
 
 	PR middle-end/78622
diff --git a/gcc/opt-functions.awk b/gcc/opt-functions.awk
index 7cf50256558..43e223c3cc7 100644
--- a/gcc/opt-functions.awk
+++ b/gcc/opt-functions.awk
@@ -61,10 +61,10 @@ function opt_args(name, flags)
 	if (flags !~ " " name "\\(")
 		return ""
 	sub(".* " name "\\(", "", flags)
-	if (flags ~ "^{")
+	if (flags ~ "^[{]")
 	{
-		sub ("^{", "", flags)
-		sub("}\\).*", "", flags)
+		sub ("^[{]", "", flags)
+		sub ("}\\).*", "", flags)
 	}
 	else
 		sub("\\).*", "", flags)