diff --git a/src/stars/Eagle/stars_part.h b/src/stars/Eagle/stars_part.h
index b8bda114a21a2161610a87a0421e0be4b4cbddf3..daf78bca9f17d7c6829b824f42d76572d1eb49c0 100644
--- a/src/stars/Eagle/stars_part.h
+++ b/src/stars/Eagle/stars_part.h
@@ -23,6 +23,9 @@
 /* Some standard headers. */
 #include <stdlib.h>
 
+/* Read chemistry */
+#include "chemistry_struct.h" 
+
 /**
  * @brief Particle fields for the star particles.
  *
@@ -51,10 +54,10 @@ struct spart {
   /*! Star mass */
   float mass;
 
-  /* Initial star mass */
+  /*! Initial star mass */
   float mass_init;
 
-  /* Stellar age */
+  /*! Stellar age */
   float age;
 
   /* Particle cutoff radius. */
@@ -72,7 +75,7 @@ struct spart {
 
   } density;
 
-  /* structure with all metallicities */
+  /*! Chemistry structure */
   struct chemistry_part_data chemistry_data;
 
 #ifdef SWIFT_DEBUG_CHECKS
@@ -120,12 +123,6 @@ struct stars_props {
 
   /*! Maximal change of h over one time-step */
   float log_max_h_change;
-
-  /*! Fixed mass ratio Ca to Si */
-  float Ca_to_Si;
-
-  /*! Fixed mass ratio S to Si */
-  float S_to_Si;
 };
 
 #endif /* SWIFT_EAGLE_STAR_PART_H */