diff --git a/ruby/lib/extism.rb b/ruby/lib/extism.rb
index 16e9359..f0649be 100644
--- a/ruby/lib/extism.rb
+++ b/ruby/lib/extism.rb
@@ -44,7 +44,7 @@ class Plugin
     rc = C.extism_call(@plugin, name, input, data.bytesize)
     if rc != 0 then
       err = C.extism_error(@plugin)
-      if err.empty? then
+      if err&.empty? then
         raise Error.new "extism_call failed"
       else raise Error.new err
       end