diff --git a/src/hydro/Default/hydro.h b/src/hydro/Default/hydro.h
index 7da005456233b800e05e75389922395ea3c1702c..b1a999b63143437cab8518cfdd96885533d7401e 100644
--- a/src/hydro/Default/hydro.h
+++ b/src/hydro/Default/hydro.h
@@ -24,6 +24,7 @@
 #include "cosmology.h"
 #include "dimension.h"
 #include "equation_of_state.h"
+#include "hydro_properties.h"
 #include "hydro_space.h"
 #include "kernel_hydro.h"
 #include "minmax.h"
diff --git a/src/hydro/Default/hydro_io.h b/src/hydro/Default/hydro_io.h
index e70a26f9edc3f7497dd4c548efd464726efe0e39..542cc21d41741a203adacb4560c6bd701e3af758 100644
--- a/src/hydro/Default/hydro_io.h
+++ b/src/hydro/Default/hydro_io.h
@@ -19,6 +19,8 @@
 #ifndef SWIFT_DEFAULT_HYDRO_IO_H
 #define SWIFT_DEFAULT_HYDRO_IO_H
 
+#include "adiabatic_index.h"
+#include "hydro.h"
 #include "io_properties.h"
 #include "kernel_hydro.h"