diff --git a/ir.cpp b/ir.cpp
index 4c1f307e8af..90df67bbf1d 100644
--- a/ir.cpp
+++ b/ir.cpp
@@ -240,6 +240,9 @@ ir_variable::ir_variable(const struct glsl_type *type, const char *name)
 {
    this->type = type;
    this->name = name;
+
+   if (type && type->base_type == GLSL_TYPE_SAMPLER)
+      this->read_only = true;
 }