diff --git a/src/debug.c b/src/debug.c
index 29076bfb61adc9c74bb4187827d3f23fc7da2214..d2fdf7c124100a87939e83fc302ab701a507805f 100644
--- a/src/debug.c
+++ b/src/debug.c
@@ -28,12 +28,17 @@
 #include "debug.h"
 
 /* Import the right hydro definition */
-#ifdef GADGET2_SPH
+#if defined(MINIMAL_SPH)
+#include "./hydro/Minimal/hydro_debug.h"
+#elif defined(GADGET2_SPH)
 #include "./hydro/Gadget2/hydro_debug.h"
-#else
+#elif defined(DEFAULT_SPH)
 #include "./hydro/Default/hydro_debug.h"
+#else
+#error "Invalid choice of SPH variant"
 #endif
 
+
 /**
  * @brief Looks for the particle with the given id and prints its information to
  *the standard output.
diff --git a/src/hydro.h b/src/hydro.h
index e6db5458595ac66c2d8292a12b251b8e45314642..4b131ea7bb65302aaa69503130f7429710dc221f 100644
--- a/src/hydro.h
+++ b/src/hydro.h
@@ -22,12 +22,17 @@
 #include "./const.h"
 
 /* Import the right functions */
-#ifdef GADGET2_SPH
-#include "./hydro/Gadget2/hydro.h"
+#if defined(MINIMAL_SPH)
+#include "./hydro/Minimal/hydro_iact.h"
+#include "./hydro/Minimal/hydro.h"
+#elif defined(GADGET2_SPH)
 #include "./hydro/Gadget2/hydro_iact.h"
-#else
-#include "./hydro/Default/hydro.h"
+#include "./hydro/Gadget2/hydro.h"
+#elif defined(DEFAULT_SPH)
 #include "./hydro/Default/hydro_iact.h"
+#include "./hydro/Default/hydro.h"
+#else
+#error "Invalid choice of SPH variant"
 #endif
 
-#endif
+#endif /* SWIFT_HYDRO_H */
diff --git a/src/hydro_io.h b/src/hydro_io.h
index 2f8c1d4cd370d2b148591387ca1fbb384b2d25d4..30d663f647c9b763e9b19177e9ba8ef374855768 100644
--- a/src/hydro_io.h
+++ b/src/hydro_io.h
@@ -22,10 +22,14 @@
 #include "./const.h"
 
 /* Import the right functions */
-#ifdef GADGET2_SPH
+#if defined(MINIMAL_SPH)
+#include "./hydro/Minimal/hydro_io.h"
+#elif defined(GADGET2_SPH)
 #include "./hydro/Gadget2/hydro_io.h"
-#else
+#elif defined(DEFAULT_SPH)
 #include "./hydro/Default/hydro_io.h"
+#else
+#error "Invalid choice of SPH variant"
 #endif
 
-#endif
+#endif /* SWIFT_HYDRO_IO_H */
diff --git a/src/part.h b/src/part.h
index 44adf56762d8a0328a8d9b5fced405930d83ac2f..168e80b68bb211d1d773f1f80f1fa9cc757edfcb 100644
--- a/src/part.h
+++ b/src/part.h
@@ -38,10 +38,14 @@
 #define xpart_align 32
 
 /* Import the right particle definition */
-#ifdef GADGET2_SPH
+#if defined(MINIMAL_SPH)
+#include "./hydro/Minimal/hydro_part.h"
+#elif defined(GADGET2_SPH)
 #include "./hydro/Gadget2/hydro_part.h"
-#else
+#elif defined(DEFAULT_SPH)
 #include "./hydro/Default/hydro_part.h"
+#else
+#error "Invalid choice of SPH variant"
 #endif
 
 #include "./gravity/Default/gravity_part.h"