diff --git a/lib/execjs/ruby_racer_runtime.rb b/lib/execjs/ruby_racer_runtime.rb
index 879e8bb..dfce4b3 100644
--- a/lib/execjs/ruby_racer_runtime.rb
+++ b/lib/execjs/ruby_racer_runtime.rb
@@ -29,7 +29,7 @@ module ExecJS
               unbox @v8_context.eval("(#{source})")
             rescue ::V8::JSError => e
               if e.value["name"] == "SyntaxError"
-                raise RuntimeError, e.message
+                raise RuntimeError, e.value.to_s
               else
                 raise ProgramError, e.value.to_s
               end
@@ -44,9 +44,9 @@ module ExecJS
             unbox @v8_context.eval(properties).call(*args)
           rescue ::V8::JSError => e
             if e.value["name"] == "SyntaxError"
-              raise RuntimeError, e.message
+              raise RuntimeError, e.value.to_s
             else
-              raise ProgramError, e.message
+              raise ProgramError, e.value.to_s
             end
           end
         end