diff --git a/src/compiler/nir/nir_constant_expressions.py b/src/compiler/nir/nir_constant_expressions.py
index 96d5255..6b4d071 100644
--- a/src/compiler/nir/nir_constant_expressions.py
+++ b/src/compiler/nir/nir_constant_expressions.py
@@ -299,6 +299,9 @@
                _src[${j}].${get_const_field(input_types[j])}[${k}],
             % endif
          % endfor
+         % for k in range(op.input_sizes[j], 4):
+            0,
+         % endfor
          };
       % endfor