diff --git a/doc/dump_image.html b/doc/dump_image.html
index 9664b05b99..cf11891de9 100644
--- a/doc/dump_image.html
+++ b/doc/dump_image.html
@@ -151,7 +151,7 @@ to colors is as follows:
 <P>and repeats itself for types > 6.  This mapping can be changed by the
 <A HREF = "dump_modify.html">dump_modify acolor</A> command.
 </P>
-<P>If <I>type</I> is specified for the <I>diameter</I> setting then the diamter of
+<P>If <I>type</I> is specified for the <I>diameter</I> setting then the diameter of
 each atom is determined by its atom type.  By default all types have
 diameter 1.0.  This mapping can be changed by the <A HREF = "dump_modify.html">dump_modify
 adiam</A> command.
diff --git a/doc/dump_image.txt b/doc/dump_image.txt
index dd1126d64f..9956cdc33f 100644
--- a/doc/dump_image.txt
+++ b/doc/dump_image.txt
@@ -138,7 +138,7 @@ type 6 = cyan :ul
 and repeats itself for types > 6.  This mapping can be changed by the
 "dump_modify acolor"_dump_modify.html command.
 
-If {type} is specified for the {diameter} setting then the diamter of
+If {type} is specified for the {diameter} setting then the diameter of
 each atom is determined by its atom type.  By default all types have
 diameter 1.0.  This mapping can be changed by the "dump_modify
 adiam"_dump_modify.html command.