Rename the new --with-optimiations flag to --enable-optimizations.
diff --git a/configure.ac b/configure.ac
index 381bab0..4e55871 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1234,8 +1234,8 @@
 AC_SUBST(DEF_MAKE_ALL_RULE)
 AC_SUBST(DEF_MAKE_RULE)
 Py_OPT='false'
-AC_MSG_CHECKING(for --with-optimizations)
-AC_ARG_WITH(optimizations, AS_HELP_STRING([--with-optimizations], [Enable expensive optimizations (PGO, maybe LTO, etc).  Disabled by default.]),
+AC_MSG_CHECKING(for --enable-optimizations)
+AC_ARG_ENABLE(optimizations, AS_HELP_STRING([--enable-optimizations], [Enable expensive optimizations (PGO, maybe LTO, etc).  Disabled by default.]),
 [
 if test "$withval" != no
 then
@@ -1351,7 +1351,7 @@
       LLVM_PROF_ERR=yes
       if test "${REQUIRE_PGO}" = "yes"
       then
-        AC_MSG_ERROR([llvm-profdata is required for a --with-optimizations build but could not be found.])
+        AC_MSG_ERROR([llvm-profdata is required for a --enable-optimizations build but could not be found.])
       fi
     fi
     ;;
@@ -1367,7 +1367,7 @@
           LLVM_PROF_ERR=yes
           if test "${REQUIRE_PGO}" = "yes"
 	  then
-	    AC_MSG_ERROR([llvm-profdata is required for a --with-optimizations build but could not be found.])
+	    AC_MSG_ERROR([llvm-profdata is required for a --enable-optimizations build but could not be found.])
 	  fi
         fi
         ;;
@@ -5379,7 +5379,7 @@
     echo "" >&AS_MESSAGE_FD
     echo "" >&AS_MESSAGE_FD
     echo "If you want a release build with all optimizations active (LTO, PGO, etc),"
-    echo "please run ./configure --with-optimizations" >&AS_MESSAGE_FD
+    echo "please run ./configure --enable-optimizations" >&AS_MESSAGE_FD
     echo "" >&AS_MESSAGE_FD
     echo "" >&AS_MESSAGE_FD
 fi