diff --git a/validate.hpp b/validate.hpp
index 7602475..8555f0e 100644
--- a/validate.hpp
+++ b/validate.hpp
@@ -77,6 +77,6 @@ string format_guess_history(vector<int> sequence, vector<int> guess) {
 
 	string r_string = "";
 	for(string s : r)
-		r_string += s;
+		r_string += s + " ";
 	return r_string;
 }