diff --git a/doc/src/sgml/ref/initdb.sgml b/doc/src/sgml/ref/initdb.sgml
index 4e339ec..31f081a 100644
--- a/doc/src/sgml/ref/initdb.sgml
+++ b/doc/src/sgml/ref/initdb.sgml
@@ -235,7 +235,7 @@ PostgreSQL documentation
 
      <varlistentry>
       <term><option>-N</option></term>
-      <term><option>--nosync</option></term>
+      <term><option>--no-sync</option></term>
       <listitem>
        <para>
         By default, <command>initdb</command> will wait for all files to be
@@ -355,7 +355,7 @@ PostgreSQL documentation
 
      <varlistentry>
       <term><option>-n</option></term>
-      <term><option>--noclean</option></term>
+      <term><option>--no-clean</option></term>
       <listitem>
        <para>
         By default, when <command>initdb</command>
diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
index 3350e13..be30543 100644
--- a/src/bin/initdb/initdb.c
+++ b/src/bin/initdb/initdb.c
@@ -2658,8 +2658,8 @@ usage(const char *progname)
 	printf(_("  -d, --debug               generate lots of debugging output\n"));
 	printf(_("  -k, --data-checksums      use data page checksums\n"));
 	printf(_("  -L DIRECTORY              where to find the input files\n"));
-	printf(_("  -n, --noclean             do not clean up after errors\n"));
-	printf(_("  -N, --nosync              do not wait for changes to be written safely to disk\n"));
+	printf(_("  -n, --no-clean            do not clean up after errors\n"));
+	printf(_("  -N, --no-sync             do not wait for changes to be written safely to disk\n"));
 	printf(_("  -s, --show                show internal settings\n"));
 	printf(_("  -S, --sync-only           only sync data directory\n"));
 	printf(_("\nOther options:\n"));
@@ -3334,8 +3334,10 @@ main(int argc, char *argv[])
 		{"version", no_argument, NULL, 'V'},
 		{"debug", no_argument, NULL, 'd'},
 		{"show", no_argument, NULL, 's'},
-		{"noclean", no_argument, NULL, 'n'},
-		{"nosync", no_argument, NULL, 'N'},
+		{"noclean", no_argument, NULL, 12},			/* deprecated */
+		{"no-clean", no_argument, NULL, 'n'},
+		{"nosync", no_argument, NULL, 13},			/* deprecated */
+		{"no-sync", no_argument, NULL, 'N'},
 		{"sync-only", no_argument, NULL, 'S'},
 		{"xlogdir", required_argument, NULL, 'X'},
 		{"data-checksums", no_argument, NULL, 'k'},
@@ -3419,10 +3421,18 @@ main(int argc, char *argv[])
 				debug = true;
 				printf(_("Running in debug mode.\n"));
 				break;
+			case 12:
+				fprintf(stderr,
+						_("WARNING: --noclean is deprecated; use --no-clean instead\n"));
+				/* fall through */
 			case 'n':
 				noclean = true;
-				printf(_("Running in noclean mode.  Mistakes will not be cleaned up.\n"));
+				printf(_("Running in no-clean mode.  Mistakes will not be cleaned up.\n"));
 				break;
+			case 13:
+				fprintf(stderr,
+						_("WARNING: --nosync is deprecated; use --no-sync instead\n"));
+				/* fall through */
 			case 'N':
 				do_sync = false;
 				break;