diff --git a/CMakeLists.txt b/CMakeLists.txt
index a8be8a332..649db52a6 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -858,6 +858,16 @@ elseif(HAVE_LIBSOCKET)
   set(CMAKE_REQUIRED_LIBRARIES socket)
 endif()
 
+if(WIN32)
+  if(ENABLE_INET_PTON)
+    # _WIN32_WINNT_VISTA (0x0600)
+    add_definitions(-D_WIN32_WINNT=0x0600)
+  else()
+    # _WIN32_WINNT_WINXP (0x0501)
+    add_definitions(-D_WIN32_WINNT=0x0501)
+  endif()
+endif()
+
 check_symbol_exists(basename      "${CURL_INCLUDES}" HAVE_BASENAME)
 check_symbol_exists(socket        "${CURL_INCLUDES}" HAVE_SOCKET)
 check_symbol_exists(select        "${CURL_INCLUDES}" HAVE_SELECT)
@@ -929,20 +939,7 @@ check_symbol_exists(fcntl          "${CURL_INCLUDES}" HAVE_FCNTL)
 check_symbol_exists(ioctl          "${CURL_INCLUDES}" HAVE_IOCTL)
 check_symbol_exists(setsockopt     "${CURL_INCLUDES}" HAVE_SETSOCKOPT)
 check_function_exists(mach_absolute_time HAVE_MACH_ABSOLUTE_TIME)
-
-# symbol exists in win32, but function does not.
-if(WIN32)
-  if(ENABLE_INET_PTON)
-    check_function_exists(inet_pton HAVE_INET_PTON)
-    # _WIN32_WINNT_VISTA (0x0600)
-    add_definitions(-D_WIN32_WINNT=0x0600)
-  else()
-    # _WIN32_WINNT_WINXP (0x0501)
-    add_definitions(-D_WIN32_WINNT=0x0501)
-  endif()
-else()
-  check_function_exists(inet_pton HAVE_INET_PTON)
-endif()
+check_symbol_exists(inet_pton      "${CURL_INCLUDES}" HAVE_INET_PTON)
 
 check_symbol_exists(fsetxattr "${CURL_INCLUDES}" HAVE_FSETXATTR)
 if(HAVE_FSETXATTR)