diff --git a/src/auto/configure b/src/auto/configure
index 9f43e8d..75f76a6 100755
--- a/src/auto/configure
+++ b/src/auto/configure
@@ -4223,7 +4223,7 @@
     OS_EXTRA_OBJ="objects/os_macosx.o objects/os_mac_conv.o"
         CPPFLAGS="$CPPFLAGS -DMACOS_X_UNIX -no-cpp-precomp"
 
-            # On IRIX 5.3, sys/types and inttypes.h are conflicting.
+                # On IRIX 5.3, sys/types and inttypes.h are conflicting.
 for ac_header in sys/types.h sys/stat.h stdlib.h string.h memory.h strings.h \
 		  inttypes.h stdint.h unistd.h
 do :
@@ -4241,16 +4241,7 @@
 done
 
 
-ac_fn_c_check_header_mongrel "$LINENO" "AvailabilityMacros.h" "ac_cv_header_AvailabilityMacros_h" "$ac_includes_default"
-if test "x$ac_cv_header_AvailabilityMacros_h" = x""yes; then :
-
-$as_echo "#define HAVE_AVAILABILITYMACROS_H 1" >>confdefs.h
-
-fi
-
-
-
-                ac_fn_c_check_header_mongrel "$LINENO" "Carbon/Carbon.h" "ac_cv_header_Carbon_Carbon_h" "$ac_includes_default"
+ac_fn_c_check_header_mongrel "$LINENO" "Carbon/Carbon.h" "ac_cv_header_Carbon_Carbon_h" "$ac_includes_default"
 if test "x$ac_cv_header_Carbon_Carbon_h" = x""yes; then :
   CARBON=yes
 fi
@@ -4272,6 +4263,13 @@
 $as_echo "no" >&6; }
 fi
 
+ac_fn_c_check_header_mongrel "$LINENO" "AvailabilityMacros.h" "ac_cv_header_AvailabilityMacros_h" "$ac_includes_default"
+if test "x$ac_cv_header_AvailabilityMacros_h" = x""yes; then :
+  HAVE_AVAILABILITYMACROS_H=1
+fi
+
+
+
 
 
 
diff --git a/src/configure.in b/src/configure.in
index 73470fc..ee70682 100644
--- a/src/configure.in
+++ b/src/configure.in
@@ -206,10 +206,6 @@
     dnl TODO: use -arch i386 on Intel machines
     CPPFLAGS="$CPPFLAGS -DMACOS_X_UNIX -no-cpp-precomp"
 
-    dnl Mac OS X 10.9+ no longer include AvailabilityMacros.h in Carbon
-    dnl so we need to include it to have access to version macros.
-    AC_CHECK_HEADER(AvailabilityMacros.h, [AC_DEFINE(HAVE_AVAILABILITYMACROS_H, 1, [ Define if we have AvailabilityMacros.h on Mac OS X ])])
-
     dnl If Carbon is found, assume we don't want X11
     dnl unless it was specifically asked for (--with-x)
     dnl or Motif, Athena or GTK GUI is used.
@@ -232,6 +228,10 @@
   AC_MSG_RESULT(no)
 fi
 
+dnl Mac OS X 10.9+ no longer include AvailabilityMacros.h in Carbon
+dnl so we need to include it to have access to version macros.
+AC_CHECK_HEADER(AvailabilityMacros.h, HAVE_AVAILABILITYMACROS_H=1)
+
 AC_SUBST(OS_EXTRA_SRC)
 AC_SUBST(OS_EXTRA_OBJ)
 
diff --git a/src/os_unix.c b/src/os_unix.c
index 80459c9..5eb0936 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -804,9 +804,7 @@
  * completely full.
  */
 
-#if defined(HAVE_AVAILABILITYMACROS_H) \
-    && defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) \
-    && (__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ >= 1090)
+#if defined(HAVE_AVAILABILITYMACROS_H)
 # include <AvailabilityMacros.h>
 #endif
 
diff --git a/src/version.c b/src/version.c
index 0c5c573..5ef4c22 100644
--- a/src/version.c
+++ b/src/version.c
@@ -739,6 +739,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    61,
+/**/
     60,
 /**/
     59,