diff --git a/README.md b/README.md
index 95ad6b6..3325a3d 100644
--- a/README.md
+++ b/README.md
@@ -140,7 +140,7 @@ def f(X):
     return np.sum(X)
     
 varbound=np.array([[0.5,1.5],[1,100],[0,1]])
-vartype=np.array([['real'],['int'],['int']])
+vartype=np.array(['real','int','int'])
 model=ga(function=f,dimension=3,variable_type_mixed=vartype,variable_boundaries=varbound)
 
 model.run()