--- configure.ac
+++ configure.ac
@@ -619,6 +619,15 @@
 AC_SUBST(API__SSIZE_T)
 AM_SUBST_NOTMAKE(API__SSIZE_T)
 
+# Try to find a thread-safe version of ttyname().
+gnupg_REPLACE_TTYNAME_R
+if test "$ac_cv_func_ttyname_r" != yes; then
+  AC_MSG_WARN([
+***
+*** ttyname() is not thread-safe and ttyname_r() does not exist
+***])
+fi
+
 # Checks for compiler features.
 if test "$GCC" = yes; then
     CFLAGS="$CFLAGS -Wall -Wcast-align -Wshadow -Wstrict-prototypes"
@@ -679,15 +679,6 @@
 
 AC_FUNC_FSEEKO
 
-# Try to find a thread-safe version of ttyname().
-gnupg_REPLACE_TTYNAME_R
-if test "$ac_cv_func_ttyname_r" != yes; then
-  AC_MSG_WARN([
-***
-*** ttyname() is not thread-safe and ttyname_r() does not exist
-***])
-fi
-
 # Try to find a thread-safe version of getenv().
 have_thread_safe_getenv=no
 jm_GLIBC21