diff --git a/src/calc.cpp b/src/calc.cpp
index d5732b330..b104c65c5 100644
--- a/src/calc.cpp
+++ b/src/calc.cpp
@@ -140,6 +140,11 @@ int main (int argc, char** argv)
     else
       e.evaluatePostfixExpression (expression, result);
 
+    // Show any debug output.
+    std::vector <std::string>::iterator i;
+    for (i = context.debugMessages.begin (); i != context.debugMessages.end (); ++i)
+      std::cout << *i << "\n";
+
     // Show the result in string form.
     std::cout << (std::string) result
               << "\n";