diff --git a/src/Val.cc b/src/Val.cc
index 4cb9d78023..2a53a32674 100644
--- a/src/Val.cc
+++ b/src/Val.cc
@@ -515,7 +515,12 @@ Val* Val::SizeVal() const
 	{
 	switch ( type->InternalType() ) {
 	case TYPE_INTERNAL_INT:
-		return new Val(llabs(val.int_val), TYPE_COUNT);
+		// Return abs value. However abs() only works on ints and llabs
+		// doesn't work on Mac OS X 10.5. So we do it by hand
+		if (val.int_val < 0)
+			return new Val(-val.int_val, TYPE_COUNT);
+		else
+			return new Val(val.int_val, TYPE_COUNT);
 
 	case TYPE_INTERNAL_UNSIGNED:
 		return new Val(val.uint_val, TYPE_COUNT);