diff --git a/src/option.c b/src/option.c
index 71b71ba..4d50a64 100644
--- a/src/option.c
+++ b/src/option.c
@@ -198,16 +198,14 @@
 	if (options[opt_idx].def_val[VI_DEFAULT] == (char_u *)0L)
 #endif
 	{
-#ifdef HAVE_AVAIL_MEM
+#if defined(HAVE_AVAIL_MEM)
 	    // Use amount of memory available at this moment.
 	    n = (mch_avail_mem(FALSE) >> 1);
-#else
-# ifdef HAVE_TOTAL_MEM
+#elif defined(HAVE_TOTAL_MEM)
 	    // Use amount of memory available to Vim.
 	    n = (mch_total_mem(FALSE) >> 1);
-# else
+#else
 	    n = (0x7fffffff >> 11);
-# endif
 #endif
 	    options[opt_idx].def_val[VI_DEFAULT] = (char_u *)n;
 	    opt_idx = findoption((char_u *)"maxmem");
@@ -266,21 +264,18 @@
     }
 #endif
 
-#if defined(FEAT_POSTSCRIPT) && (defined(MSWIN) || defined(VMS) || defined(MAC) || defined(hpux))
+#if defined(FEAT_POSTSCRIPT) && \
+	(defined(MSWIN) || defined(VMS) || defined(MAC) || defined(hpux))
     // Set print encoding on platforms that don't default to latin1
     set_string_default("penc",
 # if defined(MSWIN)
 		       (char_u *)"cp1252"
-# else
-#  ifdef VMS
+# elif defined(VMS)
 		       (char_u *)"dec-mcs"
-#  else
-#   ifdef MAC
+# elif defined(MAC)
 		       (char_u *)"mac-roman"
-#   else // HPUX
+# else // HPUX
 		       (char_u *)"hp-roman8"
-#   endif
-#  endif
 # endif
 		       );
 #endif
@@ -290,13 +285,11 @@
     set_string_default("pexpr",
 # if defined(MSWIN)
 	    (char_u *)"system('copy' . ' ' . v:fname_in . (&printdevice == '' ? ' LPT1:' : (' \"' . &printdevice . '\"'))) . delete(v:fname_in)"
-# else
-#  ifdef VMS
+# elif defined(VMS)
 	    (char_u *)"system('print/delete' . (&printdevice == '' ? '' : ' /queue=' . &printdevice) . ' ' . v:fname_in)"
 
-#  else
+# else
 	    (char_u *)"system('lpr' . (&printdevice == '' ? '' : ' -P' . &printdevice) . ' ' . v:fname_in) . delete(v:fname_in) + v:shell_error"
-#  endif
 # endif
 	    );
 #endif
@@ -430,11 +423,9 @@
 	    vim_setenv((char_u *)"LANG", (char_u *)buf);
 	}
     }
-# else
-#  ifdef MACOS_CONVERT
+# elif defined(MACOS_CONVERT)
     // Moved to os_mac_conv.c to avoid dependency problems.
     mac_lang_init();
-#  endif
 # endif
 
 # ifdef MSWIN
diff --git a/src/optiondefs.h b/src/optiondefs.h
index 9eb0e78..4f2ec4d 100644
--- a/src/optiondefs.h
+++ b/src/optiondefs.h
@@ -1148,21 +1148,17 @@
 #ifdef FEAT_QUICKFIX
 			    (char_u *)&p_gp, PV_GP,
 			    {
-# ifdef MSWIN
+# if defined(MSWIN)
 			    // may be changed to "grep -n" in os_win32.c
 			    (char_u *)"findstr /n",
-# else
-#  ifdef UNIX
+# elif defined(UNIX)
 			    // Add an extra file name so that grep will always
 			    // insert a file name in the match line.
 			    (char_u *)"grep -n $* /dev/null",
-#  else
-#   ifdef VMS
+# elif defined(VMS)
 			    (char_u *)"SEARCH/NUMBERS ",
-#   else
+# else
 			    (char_u *)"grep -n ",
-#   endif
-#  endif
 # endif
 			    (char_u *)0L}
 #else
@@ -1431,14 +1427,12 @@
 				// ( and ) are used in text separating fnames
 			    (char_u *)"@,48-57,/,\\,.,-,_,+,,,#,$,%,{,},[,],:,@-@,!,~,=",
 #else
-# ifdef AMIGA
+# if defined(AMIGA)
 			    (char_u *)"@,48-57,/,.,-,_,+,,,$,:",
-# else
-#  ifdef VMS
+# elif defined(VMS)
 			    (char_u *)"@,48-57,/,.,-,_,+,,,#,$,%,<,>,[,],:,;,~",
-#  else // UNIX et al.
+# else // UNIX et al.
 			    (char_u *)"@,48-57,/,.,-,_,+,,,#,$,%,~,=",
-#  endif
 # endif
 #endif
 				(char_u *)0L} SCTX_INIT},
@@ -1497,18 +1491,14 @@
     {"keywordprg",  "kp",   P_STRING|P_EXPAND|P_VI_DEF|P_SECURE,
 			    (char_u *)&p_kp, PV_KP,
 			    {
-#ifdef MSWIN
+#if defined(MSWIN)
 			    (char_u *)":help",
-#else
-# ifdef VMS
+#elif defined(VMS)
 			    (char_u *)"help",
-# else
-#  ifdef USEMAN_S
+#elif defined(USEMAN_S)
 			    (char_u *)"man -s",
-#  else
+#else
 			    (char_u *)"man",
-#  endif
-# endif
 #endif
 				(char_u *)0L} SCTX_INIT},
     {"langmap",     "lmap", P_STRING|P_VI_DEF|P_ONECOMMA|P_NODUP|P_SECURE,
@@ -2767,13 +2757,11 @@
 			    (char_u *)&p_viminfo, PV_NONE,
 #if defined(MSWIN)
 			    {(char_u *)"", (char_u *)"'100,<50,s10,h,rA:,rB:"}
-#else
-# ifdef AMIGA
+#elif defined(AMIGA)
 			    {(char_u *)"",
 				 (char_u *)"'100,<50,s10,h,rdf0:,rdf1:,rdf2:"}
-# else
+#else
 			    {(char_u *)"", (char_u *)"'100,<50,s10,h"}
-# endif
 #endif
 #else
 			    (char_u *)NULL, PV_NONE,
diff --git a/src/optionstr.c b/src/optionstr.c
index 5c3f76d..09e6d8a 100644
--- a/src/optionstr.c
+++ b/src/optionstr.c
@@ -949,14 +949,12 @@
 		|| check_opt_strings(p_wak, p_wak_values, FALSE) != OK)
 	    errmsg = e_invalid_argument;
 # ifdef FEAT_MENU
-#  ifdef FEAT_GUI_MOTIF
+#  if defined(FEAT_GUI_MOTIF)
 	else if (gui.in_use)
 	    gui_motif_set_mnemonics(p_wak[0] == 'y' || p_wak[0] == 'm');
-#  else
-#   ifdef FEAT_GUI_GTK
+#  elif defined(FEAT_GUI_GTK)
 	else if (gui.in_use)
 	    gui_gtk_set_mnemonics(p_wak[0] == 'y' || p_wak[0] == 'm');
-#   endif
 #  endif
 # endif
     }
diff --git a/src/version.c b/src/version.c
index 203b947..3e220f5 100644
--- a/src/version.c
+++ b/src/version.c
@@ -711,28 +711,24 @@
 #else
 	"-xim",
 #endif
-#ifdef MSWIN
+#if defined(MSWIN)
 # ifdef FEAT_XPM_W32
 	"+xpm_w32",
 # else
 	"-xpm_w32",
 # endif
-#else
-# ifdef HAVE_XPM
+#elif defined(HAVE_XPM)
 	"+xpm",
-# else
+#else
 	"-xpm",
-# endif
 #endif
 #if defined(UNIX) || defined(VMS)
-# ifdef USE_XSMP_INTERACT
+# if defined(USE_XSMP_INTERACT)
 	"+xsmp_interact",
-# else
-#  ifdef USE_XSMP
+# elif defined(USE_XSMP)
 	"+xsmp",
-#  else
+# else
 	"-xsmp",
-#  endif
 # endif
 # ifdef FEAT_XCLIPBOARD
 	"+xterm_clipboard",
@@ -751,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4694,
+/**/
     4693,
 /**/
     4692,
@@ -10454,53 +10452,35 @@
     }
 #endif
 
-#ifdef FEAT_HUGE
+#if defined(FEAT_HUGE)
     msg_puts(_("\nHuge version "));
-#else
-# ifdef FEAT_BIG
+#elif defined(FEAT_BIG)
     msg_puts(_("\nBig version "));
-# else
-#  ifdef FEAT_NORMAL
+#elif defined(FEAT_NORMAL)
     msg_puts(_("\nNormal version "));
-#  else
-#   ifdef FEAT_SMALL
+#elif defined(FEAT_SMALL)
     msg_puts(_("\nSmall version "));
-#   else
-    msg_puts(_("\nTiny version "));
-#   endif
-#  endif
-# endif
-#endif
-#ifndef FEAT_GUI
-    msg_puts(_("without GUI."));
 #else
-# ifdef FEAT_GUI_GTK
-#  ifdef USE_GTK3
+    msg_puts(_("\nTiny version "));
+#endif
+#if !defined(FEAT_GUI)
+    msg_puts(_("without GUI."));
+#elif defined(FEAT_GUI_GTK)
+# if defined(USE_GTK3)
     msg_puts(_("with GTK3 GUI."));
-#  else
-#   ifdef FEAT_GUI_GNOME
+# elif defined(FEAT_GUI_GNOME)
      msg_puts(_("with GTK2-GNOME GUI."));
-#   else
-     msg_puts(_("with GTK2 GUI."));
-#   endif
-# endif
 # else
-#  ifdef FEAT_GUI_MOTIF
-    msg_puts(_("with X11-Motif GUI."));
-#  else
-#   ifdef FEAT_GUI_HAIKU
-    msg_puts(_("with Haiku GUI."));
-#   else
-#    ifdef FEAT_GUI_PHOTON
-    msg_puts(_("with Photon GUI."));
-#    else
-#     if defined(MSWIN)
-    msg_puts(_("with GUI."));
-#     endif
-#    endif
-#   endif
-#  endif
+     msg_puts(_("with GTK2 GUI."));
 # endif
+#elif defined(FEAT_GUI_MOTIF)
+    msg_puts(_("with X11-Motif GUI."));
+#elif defined(FEAT_GUI_HAIKU)
+    msg_puts(_("with Haiku GUI."));
+#elif defined(FEAT_GUI_PHOTON)
+    msg_puts(_("with Photon GUI."));
+#elif defined(MSWIN)
+    msg_puts(_("with GUI."));
 #endif
     version_msg(_("  Features included (+) or not (-):\n"));