diff --git a/lib/inferno/dsl/oauth_credentials.rb b/lib/inferno/dsl/oauth_credentials.rb
index 392bf621a..d3738f436 100644
--- a/lib/inferno/dsl/oauth_credentials.rb
+++ b/lib/inferno/dsl/oauth_credentials.rb
@@ -80,7 +80,7 @@ def need_to_refresh?
 
         return true if expires_in.blank?
 
-        token_retrieval_time.to_i + expires_in - DateTime.now.to_i < 60
+        token_retrieval_time.to_i + expires_in.to_i - DateTime.now.to_i < 60
       end
 
       # @private