diff --git a/contrib/gcc/gcc.1 b/contrib/gcc/gcc.1
index 4e7074100418..b30ebf31f48c 100644
--- a/contrib/gcc/gcc.1
+++ b/contrib/gcc/gcc.1
@@ -265,6 +265,8 @@ in the following sections.
 \-O
 \-O2
 \-O3
+\-O0
+\-Os
 .TP
 .B Preprocessor Options
 .RI \-A assertion
@@ -2459,6 +2461,12 @@ Optimize yet more. This turns on everything
 does, along with also turning on
 .B \-finline\-functions.
 .TP
+.B \-Os
+Optimize for size. This enables all
+.B \-O2
+optimizations that do not typically increase code size.  It also performs
+further optimizations designed to reduce code size.
+.TP
 .B \-O0
 Do not optimize.
 .Sp