Fix some typos by spell checker

1 files changed, 1 insertions, 1 deletions

diff --git a/doc/extension.rdoc b/doc/extension.rdoc
index c33dea2228..f8e0a1ec3d 100644
--- a/doc/extension.rdoc
+++ b/doc/extension.rdoc
@@ -2127,7 +2127,7 @@ To make "Ractor-safe" C extension, we need to check the following points:
 (1) Do not share unshareable objects between ractors
 
 For example, C's global variable can lead sharing an unshareable objects
-betwee ractors.
+between ractors.
 
   VALUE g_var;
   VALUE set(VALUE self, VALUE v){ return g_var = v; }