diff --git a/examples/numdiff/in.numdiff b/examples/numdiff/in.numdiff
index c626366a0f..ac6c34cd52 100644
--- a/examples/numdiff/in.numdiff
+++ b/examples/numdiff/in.numdiff
@@ -6,7 +6,7 @@ atom_style      atomic
 lattice fcc 5.358000
 region box block 0 6 0 6 0 6
 create_box 1 box
-create_atoms 1box
+create_atoms 1 box
 mass 1 39.903
 
 velocity all create 10 2357 mom yes dist gaussian