diff --git a/CMakeLists.txt b/CMakeLists.txt
index 14fab9a..41d83fc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -18,10 +18,10 @@ include_directories(libsgp4)
 
 add_library(sgp4 STATIC ${SRCS})
 add_executable(sattrack sattrack/sattrack.cpp)
-target_link_libraries(sattrack sgp4)
+target_link_libraries(sattrack sgp4 rt)
 add_executable(runtest runtest/runtest.cpp)
-target_link_libraries(runtest sgp4)
+target_link_libraries(runtest sgp4 rt)
 add_executable(passpredict passpredict/passpredict.cpp)
-target_link_libraries(passpredict sgp4)
+target_link_libraries(passpredict sgp4 rt)
 
 file(COPY SGP4-VER.TLE DESTINATION ${PROJECT_BINARY_DIR})
diff --git a/libsgp4/CoordTopocentric.h b/libsgp4/CoordTopocentric.h
index 42fbeb4..8ede642 100644
--- a/libsgp4/CoordTopocentric.h
+++ b/libsgp4/CoordTopocentric.h
@@ -31,7 +31,7 @@
  * Azimuth and elevation are stored in radians. Range in kilometres. Range
  * rate in kilometres/second.
  */
-struct CoordTopocentric final
+struct CoordTopocentric
 {
 public:
     /**