diff --git a/include/VirtualMachine.h b/include/VirtualMachine.h
index cd93408c2e..6a8d8ccec6 100644
--- a/include/VirtualMachine.h
+++ b/include/VirtualMachine.h
@@ -1612,7 +1612,7 @@ private:
      *  Parse the "GRAPHICS" attribute and generates a default PORT if not
      *  defined
      */
-    void parse_graphics();
+    int parse_graphics(string& error_str);
 
     /**
      * Searches the meaningful attributes and moves them from the user template
diff --git a/src/host/Host.cc b/src/host/Host.cc
index 4f72927084..f84f3bc2d0 100644
--- a/src/host/Host.cc
+++ b/src/host/Host.cc
@@ -256,9 +256,9 @@ int Host::update_info(Template        &tmpl,
     vector<Attribute*>           ds_att;
     vector<Attribute*>           local_ds_att;
 
-    int         rc;
-    int         vmid;
-    long long   val;
+    int   rc;
+    int   vmid;
+    float val;
 
     string error_st;
 
diff --git a/src/vm/VirtualMachine.cc b/src/vm/VirtualMachine.cc
index 53b91fdaae..bc0185519d 100644
--- a/src/vm/VirtualMachine.cc
+++ b/src/vm/VirtualMachine.cc
@@ -392,7 +392,10 @@ int VirtualMachine::insert(SqlDB * db, string& error_str)
         goto error_requirements;
     }
 
-    parse_graphics();
+    if ( parse_graphics(error_str) != 0 )
+    {
+        goto error_graphics;
+    }
 
     parse_well_known_attributes();
 
@@ -418,6 +421,9 @@ error_context:
 error_requirements:
     goto error_rollback;
 
+error_graphics:
+    goto error_rollback;
+
 error_rollback:
     release_disk_images();
 
@@ -917,16 +923,14 @@ error_cleanup:
 /* -------------------------------------------------------------------------- */
 /* -------------------------------------------------------------------------- */
 
-void VirtualMachine::parse_graphics()
+int VirtualMachine::parse_graphics(string& error_str)
 {
-    int num;
-
     vector<Attribute *> array_graphics;
     VectorAttribute *   graphics;
 
     vector<Attribute *>::iterator it;
 
-    num = user_obj_template->remove("GRAPHICS", array_graphics);
+    int num = user_obj_template->remove("GRAPHICS", array_graphics);
 
     for (it=array_graphics.begin(); it != array_graphics.end(); it++)
     {
@@ -935,17 +939,20 @@ void VirtualMachine::parse_graphics()
 
     if ( num == 0 )
     {
-        return;
+        return 0;
     }
 
     graphics = dynamic_cast<VectorAttribute * >(array_graphics[0]);
 
     if ( graphics == 0 )
     {
-        return;
+        return 0;
     }
 
     string port = graphics->vector_value("PORT");
+    int    port_i;
+
+    int rc = graphics->vector_value("PORT", port_i);
 
     if ( port.empty() )
     {
@@ -966,6 +973,13 @@ void VirtualMachine::parse_graphics()
         oss << ( base_port + ( oid % (limit - base_port) ));
         graphics->replace("PORT", oss.str());
     }
+    else if ( rc == -1 || port_i < 0 )
+    {
+        error_str = "Wrong PORT number in GRAPHICS attribute";
+        return -1;
+    }
+
+    return 0;
 }
 
 /* -------------------------------------------------------------------------- */