diff --git a/src/glsl/ir_constant_expression.cpp b/src/glsl/ir_constant_expression.cpp
index 61a708f6e2d..bab7466500e 100644
--- a/src/glsl/ir_constant_expression.cpp
+++ b/src/glsl/ir_constant_expression.cpp
@@ -54,6 +54,9 @@ dot(ir_constant *op0, ir_constant *op1)
 ir_constant *
 ir_expression::constant_expression_value()
 {
+   if (this->type->is_error())
+      return NULL;
+
    ir_constant *op[2] = { NULL, NULL };
    ir_constant_data data;