diff --git a/src/auto/configure b/src/auto/configure
index ba0d0b0..ff3a63b 100755
--- a/src/auto/configure
+++ b/src/auto/configure
@@ -810,7 +810,6 @@
 enable_rubyinterp
 with_ruby_command
 enable_cscope
-enable_termtruecolor
 enable_workshop
 enable_netbeans
 enable_channel
@@ -1477,7 +1476,6 @@
   --enable-tclinterp=OPTS      Include Tcl interpreter. default=no OPTS=no/yes/dynamic
   --enable-rubyinterp=OPTS     Include Ruby interpreter.  default=no OPTS=no/yes/dynamic
   --enable-cscope         Include cscope interface.
-  --enable-termtruecolor      Include support for 24-bit colors in ISO-8613-3 compatible terminals
   --enable-workshop       Include Sun Visual Workshop support.
   --disable-netbeans      Disable NetBeans integration support.
   --disable-channel      Disable process communication support.
@@ -7218,22 +7216,6 @@
 
 fi
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking --enable-termtruecolor argument" >&5
-$as_echo_n "checking --enable-termtruecolor argument... " >&6; }
-# Check whether --enable-termtruecolor was given.
-if test "${enable_termtruecolor+set}" = set; then :
-  enableval=$enable_termtruecolor;
-else
-  enable_termtruecolor="no"
-fi
-
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $enable_termtruecolor" >&5
-$as_echo "$enable_termtruecolor" >&6; }
-if test "$enable_termtruecolor" = "yes"; then
-  $as_echo "#define FEAT_TERMTRUECOLOR 1" >>confdefs.h
-
-fi
-
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking --enable-workshop argument" >&5
 $as_echo_n "checking --enable-workshop argument... " >&6; }
 # Check whether --enable-workshop was given.
diff --git a/src/config.h.in b/src/config.h.in
index 6c0f779..9d35e48 100644
--- a/src/config.h.in
+++ b/src/config.h.in
@@ -362,9 +362,6 @@
 /* Define for linking via dlopen() or LoadLibrary() */
 #undef DYNAMIC_TCL
 
-/* Define if you want 24-bit colors in ISO-8613-3 compatible terminals. */
-#undef FEAT_TERMTRUECOLOR
-
 /* Define if you want to add support for ACL */
 #undef HAVE_POSIX_ACL
 #undef HAVE_SOLARIS_ZFS_ACL
diff --git a/src/configure.in b/src/configure.in
index d1d7838..279ed47 100644
--- a/src/configure.in
+++ b/src/configure.in
@@ -1926,15 +1926,6 @@
   AC_DEFINE(FEAT_CSCOPE)
 fi
 
-AC_MSG_CHECKING(--enable-termtruecolor argument)
-AC_ARG_ENABLE(termtruecolor,
-	[  --enable-termtruecolor      Include support for 24-bit colors in ISO-8613-3 compatible terminals], ,
-	[enable_termtruecolor="no"])
-AC_MSG_RESULT($enable_termtruecolor)
-if test "$enable_termtruecolor" = "yes"; then
-  AC_DEFINE(FEAT_TERMTRUECOLOR)
-fi
-
 AC_MSG_CHECKING(--enable-workshop argument)
 AC_ARG_ENABLE(workshop,
 	[  --enable-workshop       Include Sun Visual Workshop support.], ,
diff --git a/src/feature.h b/src/feature.h
index 75b8880..d3d768e 100644
--- a/src/feature.h
+++ b/src/feature.h
@@ -814,6 +814,13 @@
 # endif
 #endif
 
+/*
+ * +termtruecolor	'guicolor' option.
+ */
+#if (defined(FEAT_BIG) && defined(FEAT_SYN_HL)) && !defined(ALWAYS_USE_GUI)
+# define FEAT_TERMTRUECOLOR
+#endif
+
 /* Mac specific thing: Codewarrior interface. */
 #ifdef FEAT_GUI_MAC
 # define FEAT_CW_EDITOR
diff --git a/src/version.c b/src/version.c
index a4f3252..e6d04ee 100644
--- a/src/version.c
+++ b/src/version.c
@@ -754,6 +754,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1784,
+/**/
     1783,
 /**/
     1782,