diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index d6c0627251bdbc930749d617133da5333321a4f7..8d054ebaa5636286ae210cccab16e83fe64db442 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -25,9 +25,9 @@ SET(rtklib_src
 
 # application header files
 SET(headers
-    ../include/gnss_utils.h
-    ../include/observations.h
-    ../include/navigation.h)
+    ../include/gnss_utils/gnss_utils.h
+    ../include/gnss_utils/observations.h
+    ../include/gnss_utils/navigation.h)
 
 # Eigen #######
 FIND_PACKAGE(Eigen3 REQUIRED)
diff --git a/src/gnss_utils.cpp b/src/gnss_utils.cpp
index 192710aa89533d1fd448567b32e71c100a44ca63..a833cc3902e4efb0e99c64f33c51f878d49081bf 100644
--- a/src/gnss_utils.cpp
+++ b/src/gnss_utils.cpp
@@ -2,7 +2,7 @@
 
 using namespace GNSSUtils;
 
-static int getPos(Observations observations, Navigation navigation, sol_t sol)
+static int getPos(Observations & observations, Navigation & navigation, sol_t sol)
 {
   // Define observations
   std::vector<obsd_t> obs = observations.getObservations();