diff --git a/doc/kspace_modify.html b/doc/kspace_modify.html
index ac9ff227d8..b3e8d09a96 100644
--- a/doc/kspace_modify.html
+++ b/doc/kspace_modify.html
@@ -129,12 +129,6 @@ as the <I>ik</I> approach.
 <P>IMPORTANT NOTE: Currently, only the <I>pppm</I> style supports the <I>ad</I>
 option.  Support from other <I>pppm</I> variants will be added later.
 </P>
-<P>IMPORTANT NOTE: If you run the <I>ad</I> option with a constant pressure
-simulation (e.g. with <A HREF = "fix_nh.html">fix npt</A>), you may see a net
-slow-down.  This is because the <I>ad</I> option requires more expensive
-pre-computation whenever the box size changes.  This happens every
-step for constant-pressure simulations.
-</P>
 <P><B>Restrictions:</B> none
 </P>
 <P><B>Related commands:</B>
diff --git a/doc/kspace_modify.txt b/doc/kspace_modify.txt
index 47c17e04e9..01b4e8f89d 100644
--- a/doc/kspace_modify.txt
+++ b/doc/kspace_modify.txt
@@ -123,12 +123,6 @@ as the {ik} approach.
 IMPORTANT NOTE: Currently, only the {pppm} style supports the {ad}
 option.  Support from other {pppm} variants will be added later.
 
-IMPORTANT NOTE: If you run the {ad} option with a constant pressure
-simulation (e.g. with "fix npt"_fix_nh.html), you may see a net
-slow-down.  This is because the {ad} option requires more expensive
-pre-computation whenever the box size changes.  This happens every
-step for constant-pressure simulations.
-
 [Restrictions:] none
 
 [Related commands:]