diff --git a/src/libexpr/nixexpr.hh b/src/libexpr/nixexpr.hh index 69a47a5adc..674321f924 100644 --- a/src/libexpr/nixexpr.hh +++ b/src/libexpr/nixexpr.hh @@ -66,6 +66,7 @@ string showPos(ATerm pos); function to the resulting term. */ struct TermFun { + virtual ~TermFun() { } virtual ATerm operator () (ATerm e) = 0; }; ATerm bottomupRewrite(TermFun & f, ATerm e);