diff --git a/src/glsl/nir/nir_lower_variables_scalar.c b/src/glsl/nir/nir_lower_variables_scalar.c
index b754fa3f859..0b7263c88de 100644
--- a/src/glsl/nir/nir_lower_variables_scalar.c
+++ b/src/glsl/nir/nir_lower_variables_scalar.c
@@ -369,6 +369,8 @@ reg_const_load_single_instr(nir_reg_dest reg, nir_constant *constant,
          instr->value.u[i] = constant->value.u[i + offset] ?
                              NIR_TRUE : NIR_FALSE;
          break;
+      default:
+         unreachable("Invalid immediate type");
       }
    }
    instr->dest.reg = reg;