diff --git a/runtime/doc/tags b/runtime/doc/tags
index daf59a9..918e767 100644
--- a/runtime/doc/tags
+++ b/runtime/doc/tags
@@ -4479,6 +4479,9 @@
 E1381	vim9class.txt	/*E1381*
 E1382	vim9class.txt	/*E1382*
 E1383	vim9class.txt	/*E1383*
+E1387	vim9class.txt	/*E1387*
+E1388	vim9class.txt	/*E1388*
+E1389	vim9class.txt	/*E1389*
 E139	message.txt	/*E139*
 E140	message.txt	/*E140*
 E1400	builtin.txt	/*E1400*
diff --git a/runtime/doc/vim9class.txt b/runtime/doc/vim9class.txt
index a27f731..b230cb8 100644
--- a/runtime/doc/vim9class.txt
+++ b/runtime/doc/vim9class.txt
@@ -464,10 +464,10 @@
 	   echo $'the surface is {shape.Surface()}'
 	endfor
 <
-						*E1378* *E1379* *E1380*
-An interface can have only instance variables (read-only and read-write
-access) and methods.  An interface cannot contain private variables, private
-methods, class variables and class methods.
+					*E1378* *E1379* *E1380* *E1387*
+An interface can contain only object methods and read-only object variables.
+An interface cannot contain read-write and private object variables, private
+object methods, class variables and class methods.
 
 An interface can extend another interface using "extends".  The sub-interface
 inherits all the instance variables and methods from the super interface.
@@ -563,7 +563,7 @@
 
 
 A class implementing an interface ~
-						*implements* *E1346* *E1347*
+					*implements* *E1346* *E1347* *E1389*
 A class can implement one or more interfaces.  The "implements" keyword can
 only appear once *E1350* .  Multiple interfaces can be specified, separated by
 commas.  Each interface name can appear only once. *E1351*
@@ -577,7 +577,7 @@
 
 
 Items in a class ~
-						*E1318* *E1325*
+						*E1318* *E1325* *E1388*
 Inside a class, in between `:class` and `:endclass`, these items can appear:
 - An object variable declaration: >
 	this._privateVariableName: memberType