FPTOOLS_CHECK_HTYPE(ptrdiff_t)
FPTOOLS_CHECK_HTYPE(size_t)
FPTOOLS_CHECK_HTYPE(wchar_t)
-FPTOOLS_CHECK_HTYPE(sig_atomic_t)
+dnl Int32 is a HACK for non-ISO C compilers
+FPTOOLS_CHECK_HTYPE(sig_atomic_t, Int32)
FPTOOLS_CHECK_HTYPE(clock_t)
FPTOOLS_CHECK_HTYPE(time_t)