diff --git a/configure.ac b/configure.ac
index d431870725..e76f223e6c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3522,23 +3522,27 @@ if test "$want_pthreads" != "no"; then
          dnl it doesn't actually work without -lpthread
          USE_THREADS_POSIX=""
          ;;
-      *-ibm-aix*)
-         dnl Check if compiler is xlC
-         COMPILER_VERSION=`"$CC" -qversion 2>/dev/null`
-         if test x"$COMPILER_VERSION" = "x"; then
-           CFLAGS="$CFLAGS -pthread"
-         else
-           CFLAGS="$CFLAGS -qthreaded"
-         fi
-         ;;
       *)
-         CFLAGS="$CFLAGS -pthread"
          ;;
       esac
 
       dnl if it wasn't found without lib, search for it in pthread lib
       if test "$USE_THREADS_POSIX" != "1"
       then
+        case $host in
+        *-ibm-aix*)
+           dnl Check if compiler is xlC
+           COMPILER_VERSION=`"$CC" -qversion 2>/dev/null`
+           if test x"$COMPILER_VERSION" = "x"; then
+             CFLAGS="$CFLAGS -pthread"
+           else
+             CFLAGS="$CFLAGS -qthreaded"
+           fi
+           ;;
+        *)
+           CFLAGS="$CFLAGS -pthread"
+           ;;
+        esac
         # assign PTHREAD for pkg-config use
         PTHREAD=" -pthread"
         AC_CHECK_LIB(pthread, pthread_create,