diff --git a/pg-ldap-sync.gemspec b/pg-ldap-sync.gemspec
index f956836..271eae2 100644
--- a/pg-ldap-sync.gemspec
+++ b/pg-ldap-sync.gemspec
@@ -23,7 +23,7 @@ Gem::Specification.new do |spec|
 
   spec.add_runtime_dependency "net-ldap", "~> 0.16"
   spec.add_runtime_dependency "kwalify", "~> 0.7"
-  spec.add_runtime_dependency "pg", ">= 0.14", "< 2.0"
+  spec.add_runtime_dependency "pg", ">= 0.14", "<= 1.0.0"
   spec.add_runtime_dependency "net-ldap-auth_adapter-gssapi", "~> 0.2.0"
   spec.add_development_dependency "ruby-ldapserver", "~> 0.7"
   spec.add_development_dependency "minitest", "~> 5.0"