diff --git a/CMakeLists.txt b/CMakeLists.txt
index b58e579d3d..407395963c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1002,31 +1002,13 @@ if(CURL_DISABLE_LDAP)
   endif()
 endif()
 
-# Check for libidn2
-option(USE_LIBIDN2 "Use libidn2 for IDN support" ON)
-if(USE_LIBIDN2)
-  find_package(Libidn2)
-  if(LIBIDN2_FOUND)
-    set(CURL_LIBS "${LIBIDN2_LIBRARIES};${CURL_LIBS}")
-    list(APPEND CURL_LIBDIRS ${LIBIDN2_LIBRARY_DIRS})
-    set(LIBCURL_PC_REQUIRES_PRIVATE "libidn2;${LIBCURL_PC_REQUIRES_PRIVATE}")
-    include_directories(${LIBIDN2_INCLUDE_DIRS})
-    link_directories(${LIBIDN2_LIBRARY_DIRS})
-    if(LIBIDN2_CFLAGS)
-      set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${LIBIDN2_CFLAGS}")
-    endif()
-    set(HAVE_IDN2_H 1)
-    set(HAVE_LIBIDN2 1)
-  endif()
-else()
-  set(HAVE_LIBIDN2 OFF)
-endif()
-
 if(WIN32)
   option(USE_WIN32_IDN "Use WinIDN for IDN support" OFF)
   if(USE_WIN32_IDN)
     list(APPEND CURL_LIBS "normaliz")
   endif()
+else()
+  set(USE_WIN32_IDN OFF)
 endif()
 
 if(APPLE)
@@ -1042,6 +1024,28 @@ if(APPLE)
       set(USE_APPLE_IDN OFF)
     endif()
   endif()
+else()
+  set(USE_APPLE_IDN OFF)
+endif()
+
+# Check for libidn2
+option(USE_LIBIDN2 "Use libidn2 for IDN support" ON)
+set(HAVE_IDN2_H OFF)
+set(HAVE_LIBIDN2 OFF)
+if(USE_LIBIDN2 AND NOT USE_APPLE_IDN AND NOT USE_WIN32_IDN)
+  find_package(Libidn2)
+  if(LIBIDN2_FOUND)
+    set(CURL_LIBS "${LIBIDN2_LIBRARIES};${CURL_LIBS}")
+    list(APPEND CURL_LIBDIRS ${LIBIDN2_LIBRARY_DIRS})
+    set(LIBCURL_PC_REQUIRES_PRIVATE "libidn2;${LIBCURL_PC_REQUIRES_PRIVATE}")
+    include_directories(${LIBIDN2_INCLUDE_DIRS})
+    link_directories(${LIBIDN2_LIBRARY_DIRS})
+    if(LIBIDN2_CFLAGS)
+      set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${LIBIDN2_CFLAGS}")
+    endif()
+    set(HAVE_IDN2_H 1)
+    set(HAVE_LIBIDN2 1)
+  endif()
 endif()
 
 # libpsl
diff --git a/configure.ac b/configure.ac
index 95b9f9a894..d6521b8b80 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2584,102 +2584,141 @@ fi
 AM_CONDITIONAL([USE_UNICODE], [test "$want_winuni" = "yes"])
 
 dnl -------------------------------------------------
-dnl check winidn option before other IDN libraries
+dnl check WinIDN option before other IDN libraries
 dnl -------------------------------------------------
 
-AC_MSG_CHECKING([whether to enable Windows native IDN (Windows native builds only)])
-OPT_WINIDN="default"
-AC_ARG_WITH(winidn,
-AS_HELP_STRING([--with-winidn=PATH],[enable Windows native IDN])
-AS_HELP_STRING([--without-winidn], [disable Windows native IDN]),
-  OPT_WINIDN=$withval)
-case "$OPT_WINIDN" in
-  no|default)
-    dnl --without-winidn option used or configure option not specified
-    want_winidn="no"
-    AC_MSG_RESULT([no])
-    ;;
-  yes)
-    dnl --with-winidn option used without path
-    want_winidn="yes"
-    want_winidn_path="default"
-    AC_MSG_RESULT([yes])
-    ;;
-  *)
-    dnl --with-winidn option used with path
-    want_winidn="yes"
-    want_winidn_path="$withval"
-    AC_MSG_RESULT([yes ($withval)])
-    ;;
-esac
+tst_links_winidn='no'
+if test "$curl_cv_native_windows" = 'yes'; then
+  AC_MSG_CHECKING([whether to enable Windows native IDN (Windows native builds only)])
+  OPT_WINIDN="default"
+  AC_ARG_WITH(winidn,
+  AS_HELP_STRING([--with-winidn=PATH],[enable Windows native IDN])
+  AS_HELP_STRING([--without-winidn], [disable Windows native IDN]),
+    OPT_WINIDN=$withval)
+  case "$OPT_WINIDN" in
+    no|default)
+      dnl --without-winidn option used or configure option not specified
+      want_winidn="no"
+      AC_MSG_RESULT([no])
+      ;;
+    yes)
+      dnl --with-winidn option used without path
+      want_winidn="yes"
+      want_winidn_path="default"
+      AC_MSG_RESULT([yes])
+      ;;
+    *)
+      dnl --with-winidn option used with path
+      want_winidn="yes"
+      want_winidn_path="$withval"
+      AC_MSG_RESULT([yes ($withval)])
+      ;;
+  esac
 
-if test "$want_winidn" = "yes"; then
-  dnl WinIDN library support has been requested
-  clean_CFLAGS="$CFLAGS"
-  clean_CPPFLAGS="$CPPFLAGS"
-  clean_LDFLAGS="$LDFLAGS"
-  clean_LIBS="$LIBS"
-  WINIDN_LIBS="-lnormaliz"
-  WINIDN_CPPFLAGS=""
-  #
-  if test "$want_winidn_path" != "default"; then
-    dnl path has been specified
-    dnl pkg-config not available or provides no info
-    WINIDN_LDFLAGS="-L$want_winidn_path/lib$libsuff"
-    WINIDN_CPPFLAGS="-I$want_winidn_path/include"
-    WINIDN_DIR="$want_winidn_path/lib$libsuff"
-  fi
-  #
-  dnl WinIDN requires a minimum supported OS version of at least Vista (0x0600)
-  AC_COMPILE_IFELSE([
-    AC_LANG_PROGRAM([[
-      #include <windows.h>
-    ]],[[
-      #if (WINVER < 0x600) && (_WIN32_WINNT < 0x600)
-      #error
-      #endif
-    ]])
-  ],[
-  ],[
-    CFLAGS=`echo $CFLAGS | $SED -e 's/-DWINVER=[[^ ]]*//g'`
-    CFLAGS=`echo $CFLAGS | $SED -e 's/-D_WIN32_WINNT=[[^ ]]*//g'`
-    CPPFLAGS=`echo $CPPFLAGS | $SED -e 's/-DWINVER=[[^ ]]*//g'`
-    CPPFLAGS=`echo $CPPFLAGS | $SED -e 's/-D_WIN32_WINNT=[[^ ]]*//g'`
-    WINIDN_CPPFLAGS="$WINIDN_CPPFLAGS -DWINVER=0x0600"
-  ])
-  #
-  CPPFLAGS="$CPPFLAGS $WINIDN_CPPFLAGS"
-  LDFLAGS="$LDFLAGS $WINIDN_LDFLAGS"
-  LIBS="$WINIDN_LIBS $LIBS"
-  #
-  AC_MSG_CHECKING([if IdnToUnicode can be linked])
-  AC_LINK_IFELSE([
-    AC_LANG_PROGRAM([[
-      #include <windows.h>
-    ]],[[
-      IdnToUnicode(0, NULL, 0, NULL, 0);
-    ]])
-  ],[
-    AC_MSG_RESULT([yes])
-    tst_links_winidn="yes"
-  ],[
-    AC_MSG_RESULT([no])
-    tst_links_winidn="no"
-  ])
-  #
-  if test "$tst_links_winidn" = "yes"; then
-    AC_DEFINE(USE_WIN32_IDN, 1, [Define to 1 if you have the `normaliz' (WinIDN) library (-lnormaliz).])
-    AC_SUBST([IDN_ENABLED], [1])
-    curl_idn_msg="enabled (Windows-native)"
-  else
-    AC_MSG_WARN([Cannot find libraries for IDN support: IDN disabled])
-    CFLAGS="$clean_CFLAGS"
-    CPPFLAGS="$clean_CPPFLAGS"
-    LDFLAGS="$clean_LDFLAGS"
-    LIBS="$clean_LIBS"
+  if test "$want_winidn" = "yes"; then
+    dnl WinIDN library support has been requested
+    clean_CFLAGS="$CFLAGS"
+    clean_CPPFLAGS="$CPPFLAGS"
+    clean_LDFLAGS="$LDFLAGS"
+    clean_LIBS="$LIBS"
+    WINIDN_LIBS="-lnormaliz"
+    WINIDN_CPPFLAGS=""
+    #
+    if test "$want_winidn_path" != "default"; then
+      dnl path has been specified
+      dnl pkg-config not available or provides no info
+      WINIDN_LDFLAGS="-L$want_winidn_path/lib$libsuff"
+      WINIDN_CPPFLAGS="-I$want_winidn_path/include"
+      WINIDN_DIR="$want_winidn_path/lib$libsuff"
+    fi
+    #
+    dnl WinIDN requires a minimum supported OS version of at least Vista (0x0600)
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        #include <windows.h>
+      ]],[[
+        #if (WINVER < 0x600) && (_WIN32_WINNT < 0x600)
+        #error
+        #endif
+      ]])
+    ],[
+    ],[
+      CFLAGS=`echo $CFLAGS | $SED -e 's/-DWINVER=[[^ ]]*//g'`
+      CFLAGS=`echo $CFLAGS | $SED -e 's/-D_WIN32_WINNT=[[^ ]]*//g'`
+      CPPFLAGS=`echo $CPPFLAGS | $SED -e 's/-DWINVER=[[^ ]]*//g'`
+      CPPFLAGS=`echo $CPPFLAGS | $SED -e 's/-D_WIN32_WINNT=[[^ ]]*//g'`
+      WINIDN_CPPFLAGS="$WINIDN_CPPFLAGS -DWINVER=0x0600"
+    ])
+    #
+    CPPFLAGS="$CPPFLAGS $WINIDN_CPPFLAGS"
+    LDFLAGS="$LDFLAGS $WINIDN_LDFLAGS"
+    LIBS="$WINIDN_LIBS $LIBS"
+    #
+    AC_MSG_CHECKING([if IdnToUnicode can be linked])
+    AC_LINK_IFELSE([
+      AC_LANG_PROGRAM([[
+        #include <windows.h>
+      ]],[[
+        IdnToUnicode(0, NULL, 0, NULL, 0);
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_links_winidn="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_links_winidn="no"
+    ])
+    #
+    if test "$tst_links_winidn" = "yes"; then
+      AC_DEFINE(USE_WIN32_IDN, 1, [Define to 1 if you have the `normaliz' (WinIDN) library (-lnormaliz).])
+      AC_SUBST([IDN_ENABLED], [1])
+      curl_idn_msg="enabled (Windows-native)"
+    else
+      AC_MSG_WARN([Cannot find libraries for IDN support: IDN disabled])
+      CFLAGS="$clean_CFLAGS"
+      CPPFLAGS="$clean_CPPFLAGS"
+      LDFLAGS="$clean_LDFLAGS"
+      LIBS="$clean_LIBS"
+    fi
   fi
 fi
 
+dnl **********************************************************************
+dnl Check for the presence of AppleIDN
+dnl **********************************************************************
+
+tst_links_appleidn='no'
+case $host_os in
+  darwin*)
+    AC_MSG_CHECKING([whether to build with Apple IDN])
+    OPT_IDN="default"
+    AC_ARG_WITH(apple-idn,
+    AS_HELP_STRING([--with-apple-idn],[Enable AppleIDN])
+    AS_HELP_STRING([--without-apple-idn],[Disable AppleIDN]),
+      [OPT_IDN=$withval])
+    case "$OPT_IDN" in
+      yes)
+        dnl --with-apple-idn option used
+        AC_MSG_RESULT([yes, check])
+        AC_CHECK_LIB(icucore, uidna_openUTS46,
+        [
+          AC_CHECK_HEADERS(unicode/uidna.h,
+            curl_idn_msg="enabled (AppleIDN)"
+            AC_DEFINE(USE_APPLE_IDN, 1, [if AppleIDN])
+            AC_SUBST(USE_APPLE_IDN, [1])
+            AC_SUBST([IDN_ENABLED], [1])
+            LIBS="-licucore -liconv $LIBS"
+            tst_links_appleidn='yes'
+          )
+        ])
+        ;;
+      *)
+        AC_MSG_RESULT([no])
+        ;;
+    esac
+    ;;
+esac
+
 dnl **********************************************************************
 dnl Check for the presence of libidn2
 dnl **********************************************************************
@@ -2693,6 +2732,9 @@ AS_HELP_STRING([--without-libidn2],[Disable libidn2 usage]),
 if test "x$tst_links_winidn" = "xyes"; then
   want_idn="no"
   AC_MSG_RESULT([no (using WinIDN instead)])
+elif test "x$tst_links_appleidn" = "xyes"; then
+  want_idn="no"
+  AC_MSG_RESULT([no (using AppleIDN instead)])
 else
   case "$OPT_IDN" in
     no)
@@ -2811,44 +2853,6 @@ if test "$want_idn" = "yes"; then
   fi
 fi
 
-dnl **********************************************************************
-dnl Check for the presence of AppleIDN
-dnl **********************************************************************
-
-case $host_os in
-  darwin*)
-    AC_MSG_CHECKING([whether to build with Apple IDN])
-    OPT_IDN="default"
-    AC_ARG_WITH(apple-idn,
-    AS_HELP_STRING([--with-apple-idn],[Enable AppleIDN])
-    AS_HELP_STRING([--without-apple-idn],[Disable AppleIDN]),
-      [OPT_IDN=$withval])
-    if test "x$want_idn" != "xno" -a "x$OPT_IDN" != "xyes"; then
-      want_appleidn="no"
-    else
-      case "$OPT_IDN" in
-        no)
-          dnl --without-apple-idn option used
-          AC_MSG_RESULT([no])
-          ;;
-        *)
-          AC_MSG_RESULT([yes, check])
-          AC_CHECK_LIB(icucore, uidna_openUTS46,
-          [
-            AC_CHECK_HEADERS(unicode/uidna.h,
-              curl_idn_msg="enabled (AppleIDN)"
-              AC_DEFINE(USE_APPLE_IDN, 1, [if AppleIDN])
-              AC_SUBST(USE_APPLE_IDN, [1])
-              AC_SUBST([IDN_ENABLED], [1])
-              LIBS="-licucore -liconv $LIBS"
-            )
-          ])
-          ;;
-      esac
-    fi
-    ;;
-esac
-
 dnl **********************************************************************
 dnl Check for nghttp2
 dnl **********************************************************************