diff --git a/doc/mkimage.1 b/doc/mkimage.1
index 7985f5a..f27da6b 100644
--- a/doc/mkimage.1
+++ b/doc/mkimage.1
@@ -41,22 +41,22 @@
 
 .TP
 .BI "\-A [" "architecture" "]"
-Set architecture. Pass -h as the architecture to see the list of supported architectures.
+Set architecture. Pass \-h as the architecture to see the list of supported architectures.
 
 .TP
 .BI "\-O [" "os" "]"
 Set operating system. bootm command of u-boot changes boot method by os type.
-Pass -h as the OS to see the list of supported OS.
+Pass \-h as the OS to see the list of supported OS.
 
 .TP
 .BI "\-T [" "image type" "]"
 Set image type.
-Pass -h as the image to see the list of supported image type.
+Pass \-h as the image to see the list of supported image type.
 
 .TP
 .BI "\-C [" "compression type" "]"
 Set compression type.
-Pass -h as the compression to see the list of supported compression type.
+Pass \-h as the compression to see the list of supported compression type.
 
 .TP
 .BI "\-a [" "load addess" "]"