diff --git a/src/DynareBison.yy b/src/DynareBison.yy
index f16ae32356cdb247ef962a1628f585e5b507e8f9..254ee7fa6e0e1e2a16b342c9f268303ad12c2211 100644
--- a/src/DynareBison.yy
+++ b/src/DynareBison.yy
@@ -2018,7 +2018,7 @@ estimation_options : o_datafile
                    ;
 
 name_value_pair : QUOTED_STRING COMMA QUOTED_STRING
-                  { $$ = "''" + $1 + "'', ''" + $3 + "''"; }
+                  { $$ = "''" + $1 + "'',''" + $3 + "''"; }
                 | QUOTED_STRING COMMA signed_number
                   { $$ = "''" + $1 + "''," + $3; }
                 ;