diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 91b970a3706..cf532f2cca0 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2012-11-05  Marc Glisse  <marc.glisse@inria.fr>
+
+	* fold-const.c (fold_unary_loc): Disable conversion optimization
+	for void type.
+
 2012-11-04  Thomas Schwinge  <thomas@codesourcery.com>
 
 	* configure: Regenerate.
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 0caca2e5794..62a4e218968 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -7749,7 +7749,8 @@ fold_unary_loc (location_t loc, enum tree_code code, tree type, tree op0)
 	    return build2_loc (loc, TREE_CODE (op0), type,
 			       TREE_OPERAND (op0, 0),
 			       TREE_OPERAND (op0, 1));
-	  else if (!INTEGRAL_TYPE_P (type) && TREE_CODE (type) != VECTOR_TYPE)
+	  else if (!INTEGRAL_TYPE_P (type) && !VOID_TYPE_P (type)
+		   && TREE_CODE (type) != VECTOR_TYPE)
 	    return build3_loc (loc, COND_EXPR, type, op0,
 			       constant_boolean_node (true, type),
 			       constant_boolean_node (false, type));