diff --git a/openql/openql.h b/openql/openql.h
index 9f71995d2..749522a9e 100644
--- a/openql/openql.h
+++ b/openql/openql.h
@@ -186,7 +186,7 @@ class Kernel
         ql_kernel->display();
     }
 
-    void gate(std::string name, std::vector<size_t> qubits={}, size_t duration=0, double angle=0.0)
+    void gate(std::string name, std::vector<size_t> qubits, size_t duration=0, double angle=0.0)
     {
         ql_kernel->gate(name, qubits, duration, angle);
     }
diff --git a/ql/utils.h b/ql/utils.h
index 4223c8b8c..ad3875cbd 100644
--- a/ql/utils.h
+++ b/ql/utils.h
@@ -22,7 +22,7 @@
 size_t MAX_CYCLE = std::numeric_limits<int>::max();
 
 #if defined(_WIN32)
-
+#include <direct.h>
 #else 
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -38,7 +38,7 @@ namespace ql
         void make_output_dir(std::string dir)
         {
             #if defined(_WIN32)
-            _mkdir(strPath.c_str());
+            _mkdir(dir.c_str());
             #else 
             mkdir(dir.c_str(), S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH);
             #endif