diff --git a/Makefile.am b/Makefile.am
index 0af391e8e..6f07c5bea 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,5 +1,3 @@
-< contrib/libtests/timepng.o: pnglibconf.h
-
 # Makefile.am:
 #   Source file for Makefile.in (and hence Makefile)
 #
@@ -9,7 +7,10 @@ PNGLIB_BASENAME= libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@
 ACLOCAL_AMFLAGS = -I scripts
 
 # test programs - run on make check, make distcheck
-check_PROGRAMS= pngtest pngunknown pngstest pngvalid pngimage timepng
+check_PROGRAMS= pngtest pngunknown pngstest pngvalid pngimage
+if HAVE_CLOCK_GETTIME
+check_PROGRAMS += timepng
+endif
 
 # Utilities - installed
 bin_PROGRAMS= pngfix png-fix-itxt
diff --git a/configure.ac b/configure.ac
index 445c8ecb2..8c9465532 100644
--- a/configure.ac
+++ b/configure.ac
@@ -136,6 +136,11 @@ AC_C_RESTRICT
 AC_CHECK_FUNCS([memset memcpy strncpy],,
                AC_MSG_FAILURE([missing ANSI-C functions]))
 
+# Some later POSIX 1003.1 functions are required for test programs, failure here
+# is soft (the corresponding test program is not built).
+AC_CHECK_FUNC([clock_gettime],,[AC_MSG_WARN([not building timepng])])
+AM_CONDITIONAL([HAVE_CLOCK_GETTIME], [test "$ac_cv_func_clock_gettime" = "yes"])
+
 # floor and ceil are required for FLOATING_POINT, but they can be turned off on
 # the configure command line (and they are independent.)  Default is to 'on'
 AC_ARG_ENABLE([floating-point],