diff --git a/src/glsl/ir.cpp b/src/glsl/ir.cpp
index a3623b31e5d..95689dc10b0 100644
--- a/src/glsl/ir.cpp
+++ b/src/glsl/ir.cpp
@@ -272,6 +272,7 @@ ir_expression::ir_expression(int op, ir_rvalue *op0)
 
    case ir_unop_f2i:
    case ir_unop_b2i:
+   case ir_unop_u2i:
       this->type = glsl_type::get_instance(GLSL_TYPE_INT,
 					   op0->type->vector_elements, 1);
       break;
@@ -289,6 +290,11 @@ ir_expression::ir_expression(int op, ir_rvalue *op0)
 					   op0->type->vector_elements, 1);
       break;
 
+   case ir_unop_i2u:
+      this->type = glsl_type::get_instance(GLSL_TYPE_UINT,
+					   op0->type->vector_elements, 1);
+      break;
+
    case ir_unop_noise:
       this->type = glsl_type::float_type;
       break;
@@ -419,6 +425,8 @@ static const char *const operator_strs[] = {
    "i2b",
    "b2i",
    "u2f",
+   "i2u",
+   "u2i",
    "any",
    "trunc",
    "ceil",
diff --git a/src/glsl/ir.h b/src/glsl/ir.h
index 9d6ce7eaa20..42a3936976a 100644
--- a/src/glsl/ir.h
+++ b/src/glsl/ir.h
@@ -789,6 +789,8 @@ enum ir_expression_operation {
    ir_unop_i2b,      /**< int-to-boolean conversion */
    ir_unop_b2i,      /**< Boolean-to-int conversion */
    ir_unop_u2f,      /**< Unsigned-to-float conversion. */
+   ir_unop_i2u,      /**< Integer-to-unsigned conversion. */
+   ir_unop_u2i,      /**< Unsigned-to-integer conversion. */
    ir_unop_any,
 
    /**
diff --git a/src/glsl/ir_constant_expression.cpp b/src/glsl/ir_constant_expression.cpp
index 2a308489656..f0299a2c4a0 100644
--- a/src/glsl/ir_constant_expression.cpp
+++ b/src/glsl/ir_constant_expression.cpp
@@ -166,7 +166,18 @@ ir_expression::constant_expression_value()
 	 data.b[c] = op[0]->value.u[c] ? true : false;
       }
       break;
-
+   case ir_unop_u2i:
+      assert(op[0]->type->base_type == GLSL_TYPE_UINT);
+      for (unsigned c = 0; c < op[0]->type->components(); c++) {
+	 data.i[c] = op[0]->value.u[c];
+      }
+      break;
+   case ir_unop_i2u:
+      assert(op[0]->type->base_type == GLSL_TYPE_INT);
+      for (unsigned c = 0; c < op[0]->type->components(); c++) {
+	 data.u[c] = op[0]->value.i[c];
+      }
+      break;
    case ir_unop_any:
       assert(op[0]->type->is_boolean());
       data.b[0] = false;
diff --git a/src/glsl/ir_validate.cpp b/src/glsl/ir_validate.cpp
index 7b1c19d65aa..41ffdfdbcc7 100644
--- a/src/glsl/ir_validate.cpp
+++ b/src/glsl/ir_validate.cpp
@@ -280,6 +280,14 @@ ir_validate::visit_leave(ir_expression *ir)
       assert(ir->operands[0]->type->base_type == GLSL_TYPE_UINT);
       assert(ir->type->base_type == GLSL_TYPE_FLOAT);
       break;
+   case ir_unop_i2u:
+      assert(ir->operands[0]->type->base_type == GLSL_TYPE_INT);
+      assert(ir->type->base_type == GLSL_TYPE_UINT);
+      break;
+   case ir_unop_u2i:
+      assert(ir->operands[0]->type->base_type == GLSL_TYPE_UINT);
+      assert(ir->type->base_type == GLSL_TYPE_INT);
+      break;
 
    case ir_unop_any:
       assert(ir->operands[0]->type->base_type == GLSL_TYPE_BOOL);