diff --git a/instana.gemspec b/instana.gemspec
index 73774fe9..129c172f 100644
--- a/instana.gemspec
+++ b/instana.gemspec
@@ -40,7 +40,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "appraisal"
   spec.add_development_dependency "fakefs"
 
-  spec.add_runtime_dependency('base64', '>= 0.1')
+  spec.add_runtime_dependency('base64', '>= 0.1.0')
   spec.add_runtime_dependency('concurrent-ruby', '>= 1.1')
   spec.add_runtime_dependency('csv', '>= 0.1')
   spec.add_runtime_dependency('sys-proctable', '>= 1.2.2')