Index: drivers/telescope/CMakeLists.txt
--- drivers/telescope/CMakeLists.txt.orig
+++ drivers/telescope/CMakeLists.txt
@@ -14,7 +14,7 @@ if(NOT WIN32)
     set_target_properties(indilx200 PROPERTIES COMPILE_FLAGS "-fPIC")
 endif(NOT WIN32)
 
-target_compile_definitions(indilx200 PRIVATE _XOPEN_SOURCE=700 HAVE_LIBNOVA)
+target_compile_definitions(indilx200 PRIVATE HAVE_LIBNOVA)
 set_target_properties(indilx200 PROPERTIES VERSION ${CMAKE_INDI_VERSION_STRING} SOVERSION ${INDI_SOVERSION} OUTPUT_NAME indilx200)
 
 target_link_libraries(indilx200 indidevice $<$<PLATFORM_ID:CYGWIN>:indidriver>)
@@ -44,7 +44,7 @@ add_executable(indi_lx200_TeenAstro
     lx200driver.cpp
     lx200_TeenAstro.cpp)
 
-target_compile_definitions(indi_lx200_TeenAstro PRIVATE _XOPEN_SOURCE=700)
+target_compile_definitions(indi_lx200_TeenAstro PRIVATE)
 target_link_libraries(indi_lx200_TeenAstro indidriver)
 
 install(TARGETS indi_lx200_TeenAstro RUNTIME DESTINATION bin)
@@ -78,6 +78,8 @@ add_executable(indi_lx200generic
 
 if(CMAKE_SYSTEM_NAME MATCHES "FreeBSD")
     target_compile_definitions(indi_lx200generic PRIVATE -D_XOPEN_SOURCE=700)
+ELSEIF(CMAKE_SYSTEM_NAME MATCHES "OpenBSD")
+    target_compile_definitions(indi_lx200generic PRIVATE)
 ELSE()
     target_compile_definitions(indi_lx200generic PRIVATE -D_XOPEN_SOURCE=600 -D_POSIX_C_SOURCE=200809L)
 ENDIF()
@@ -124,7 +126,7 @@ add_executable(indi_rainbow_telescope
     rainbow.cpp
     lx200driver.cpp)
 
-target_compile_definitions(indi_rainbow_telescope PRIVATE _XOPEN_SOURCE=700)
+target_compile_definitions(indi_rainbow_telescope PRIVATE)
 
 target_link_libraries(indi_rainbow_telescope indidriver)
 
