diff --git a/runtime/doc/eval.txt b/runtime/doc/eval.txt
index fe10e34..6238723 100644
--- a/runtime/doc/eval.txt
+++ b/runtime/doc/eval.txt
@@ -2672,6 +2672,7 @@
 test_null_string()		String	null value for testing
 test_option_not_set({name})	none	reset flag indicating option was set
 test_override({expr}, {val})	none	test with Vim internal overrides
+test_refcount({expr})		Number	get the reference count of {expr}
 test_scrollbar({which}, {value}, {dragging})
 				none	scroll in the GUI for testing
 test_settime({expr})		none	set current time for testing
@@ -9589,6 +9590,11 @@
 <		The value of "starting" is saved.  It is restored by: >
 			call test_override('starting', 0)
 
+test_refcount({expr})					*test_refcount()*
+		Return the reference count of {expr}.  When {expr} is of a
+		type that does not have a reference count, returns -1.  Only
+		to be used for testing.
+
 test_scrollbar({which}, {value}, {dragging})		*test_scrollbar()*
 		Pretend using scrollbar {which} to move it to position
 		{value}.  {which} can be: