diff --git a/src/libexpr/gc-small-vector.hh b/src/libexpr/gc-small-vector.hh
index 7f4f08fc7..94c3ad28b 100644
--- a/src/libexpr/gc-small-vector.hh
+++ b/src/libexpr/gc-small-vector.hh
@@ -4,6 +4,7 @@
 
 #if HAVE_BOEHMGC
 
+#define GC_INCLUDE_NEW
 #include <gc/gc.h>
 #include <gc/gc_cpp.h>
 #include <gc/gc_allocator.h>
@@ -39,4 +40,4 @@ using SmallValueVector = SmallVector<Value *, nItems>;
 template <size_t nItems>
 using SmallTemporaryValueVector = SmallVector<Value, nItems>;
 
-}
\ No newline at end of file
+}