diff --git a/src/Makefile.am b/src/Makefile.am
index 3c2946dd889fee325820d9c4546abb3b511fb42d..a7bc4774ea3fb162a2b3af1ea825607659e34c6a 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -71,7 +71,7 @@ nobase_noinst_HEADERS = align.h approx_math.h atomic.h barrier.h cycle.h error.h
 		 gravity/Default/gravity_debug.h gravity/Default/gravity_part.h  \
 		 sourceterms.h \
 		 equation_of_state.h \
-		 equation_of_state/ideal_gas/equation_of_state.h equation_of_state/isothermal/equation_of_state.h
+		 equation_of_state/ideal_gas/equation_of_state.h equation_of_state/isothermal/equation_of_state.h \
 	 	 hydro.h hydro_io.h \
 		 hydro/Minimal/hydro.h hydro/Minimal/hydro_iact.h hydro/Minimal/hydro_io.h \
                  hydro/Minimal/hydro_debug.h hydro/Minimal/hydro_part.h \