diff --git a/src/mrw/exec.hxx b/src/mrw/exec.hxx
index 9030f1b..798f15d 100644
--- a/src/mrw/exec.hxx
+++ b/src/mrw/exec.hxx
@@ -46,6 +46,7 @@
 #include <memory>
 #include <mrw/exception.hxx>
 #include <mrw/unistd.hxx>
+#include <mrw/checkcxx11.hxx>
 
 namespace mrw {