2 files changed, 10 insertions, 4 deletions

diff --git a/docs/index.html b/docs/index.html
index 9e28f76..d857579 100644
--- a/docs/index.html
+++ b/docs/index.html
@@ -1747,7 +1747,7 @@
 <p></p>
 
 <table border="1" bgcolor="#E0E0FF" cellpadding="10" style="width:50%"><tr><td><pre>
-        {[{linda, slot, when, period}[,...]]} = lanes.timers()
+        {[{linda, slot, {when [, period]}}[,...]]} = lanes.timers()
 </pre></td></tr></table>
 
 <p>
diff --git a/tests/timer.lua b/tests/timer.lua
index ac8b385..80a302d 100644
--- a/tests/timer.lua
+++ b/tests/timer.lua
@@ -79,10 +79,16 @@ assert( caught[T2] )
 
 
 PRINT( "\n*** Listing timers ***\n" )
-local r = lanes.timers() -- list of {linda, key, {}}
+local r = lanes.timers() -- list of {linda, key, {when [, period]}}
 for _,t in ipairs( r) do
-    local linda, key, timer = t[1], t[2], t[3]
-    print( tostring( linda), key, timer[1], timer[2])
+    local linda, key, timer_data = t[1], t[2], t[3]
+    -- verify the structure: 3 elements, third is a nested table (not a flat 4-element entry)
+    assert(t[4] == nil, "timer entry must have exactly 3 elements, not 4 (flat structure)")
+    assert(type(linda) == "userdata", "timer entry [1] must be a linda userdata")
+    assert(type(timer_data) == "table", "timer entry [3] must be a table {when [, period]}, not a flat value")
+    assert(type(timer_data[1]) == "number", "timer_data[1] (when) must be a number")
+    assert(timer_data[2] == nil or type(timer_data[2]) == "number", "timer_data[2] (period) must be a number or nil")
+    print( tostring( linda), key, timer_data[1], timer_data[2])
 end