diff --git a/refinerycms-calendar.gemspec b/refinerycms-calendar.gemspec
index 57b8a1e..93b899c 100644
--- a/refinerycms-calendar.gemspec
+++ b/refinerycms-calendar.gemspec
@@ -12,8 +12,5 @@ Gem::Specification.new do |s|
   s.files             = Dir["{app,config,db,lib,vendor}/**/*"] + ["readme.md"]
 
   # Runtime dependencies
-  s.add_dependency             'refinerycms-core',    '~> 2.1.0'
-
-  # Development dependencies (usually used for testing)
-  s.add_development_dependency 'refinerycms-testing', '~> 2.1.0'
-end
+  s.add_dependency             'refinerycms-core',    '~> 3.0.0'
+end
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