diff --git a/integrity.gemspec b/integrity.gemspec
index 30ee1763..3fc1a838 100644
--- a/integrity.gemspec
+++ b/integrity.gemspec
@@ -21,7 +21,7 @@ Gem::Specification.new do |s|
   s.add_dependency "sinatra", [">= 0.9.1.1"]
   s.add_dependency "sinatra-authorization"
   s.add_dependency "haml",    [">= 2.0.0"]
-  s.add_dependency "data_mapper", [">= 0.9.10"]
+  s.add_dependency "data_mapper", ["= 0.9.10"]
   s.add_dependency "uuidtools"   # required by dm-types
   s.add_dependency "bcrypt-ruby" # required by dm-types
   s.add_dependency "json"