diff --git a/lib/active_interaction/base.rb b/lib/active_interaction/base.rb
index 511f6991..b4f332b4 100644
--- a/lib/active_interaction/base.rb
+++ b/lib/active_interaction/base.rb
@@ -121,7 +121,9 @@ def self.run(options = {})
     # @return The return value of {#execute}.
     def self.run!(options = {})
       outcome = run(options)
-      raise InteractionInvalid if outcome.invalid?
+      if outcome.invalid?
+        raise InteractionInvalid, outcome.errors.full_messages.join(', ')
+      end
       outcome.result
     end