diff --git a/configure.ac b/configure.ac
index 1792464798c..d6c2ee70f12 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1578,9 +1578,6 @@ fi
 
 #### Choose a compiler.
 
-dnl Don't bother to test for C89.
-AC_DEFUN([_AC_PROG_CC_C89], [$2])
-
 dnl Sets GCC=yes if using gcc.
 AC_PROG_CC([gcc cc cl clang "$XCRUN gcc" "$XCRUN clang"])
 
@@ -1589,11 +1586,6 @@ if test -n "$XCRUN"; then
   test -n "$AR" && export AR
 fi
 
-dnl Emacs needs C99 or later.
-gl_PROG_CC_C99
-
-AC_PROG_CC_C_O
-
 if test x$GCC = xyes; then
   test "x$GCC_TEST_OPTIONS" != x && CC="$CC $GCC_TEST_OPTIONS"
 fi