diff --git a/3_effects.rst b/3_effects.rst
index 6d9bd7c..42ccbd9 100644
--- a/3_effects.rst
+++ b/3_effects.rst
@@ -222,7 +222,7 @@ GC safety
 
   import threadpool, tables, strutils
 
-  {.pragma isolated, threadvar.}
+  {.pragma: isolated, threadvar.}
 
   var tab {.isolated.}: CountTable[string]