doc/INSTALL                            |  2 +-
 doc/NEWS                               |  5 +++++
 doc/cmd/redo-ifchange                  |  2 ++
 run.go                                 |  3 +++
 t/goredo-build-uuid-for-fdood.t        |  3 +++
 t/goredo-double-consideration.t        |  5 ++++-
 t/redo-sh.tests/nothing_written_1/test | 10 ++++++++++
 t/redo-sh.tests/nothing_written_2/test | 14 ++++++++++++++
 t/redo-sh.tests/parallel_1/test        |  1 +
 t/redosh-nothing_written_1.t           |  1 +
 t/redosh-nothing_written_2.t           |  1 +
 usage.go                               |  2 +-

diff --git a/doc/INSTALL b/doc/INSTALL
index 5d99941b3c134c991f0c01d6adbba8b2332d2cea8049f56e392cfa4aa07ae040..49d97e2cadabd55a9a856e1175bc31ad5c3e187955ab64c1b2effa8624a25385 100644
--- a/doc/INSTALL
+++ b/doc/INSTALL
@@ -11,7 +11,7 @@ => https://github.com/NixOS/nixpkgs/tree/master/pkgs/by-name/go/goredo NixOS packages
 
 Preferable way is to [Download] tarball with the signature from website:
 
-    $ v=2.8.0
+    $ v=2.9.0
     $ [fetch|wget] http://www.goredo.cypherpunks.su/download/goredo-$v.tar.zst
     $ [fetch|wget] http://www.goredo.cypherpunks.su/download/goredo-$v.tar.zst.{asc,sig,cm}
     [Integrity] verify
diff --git a/doc/NEWS b/doc/NEWS
index 650db08a7ded1e74fc5ea5f98b7d964df8ff09c7d1ed7e8f46539ee14e7db625..73ea890e71fdb02332596720e7c48a1e29a9ff2a3fe5904a8bbd7106aba35c1e 100644
--- a/doc/NEWS
+++ b/doc/NEWS
@@ -1,3 +1,8 @@
+A 2.9.0
+2.9.0
+    * Warn if non-top target did not write anything.
+      Idea was borrowed from redo-sh.
+
 A 2.8.0
 2.8.0
     * Fix always-OOD .do-targets with nearby default.do.
diff --git a/doc/cmd/redo-ifchange b/doc/cmd/redo-ifchange
index 39ff90f4067546fa51bc5ab9cd6ecfff232716218e7d8271738a79a04f6d8b58..93094714fc8ef2e1472b9e7169aaaf546e1759c44672781e70b587e4d99aa2de 100644
--- a/doc/cmd/redo-ifchange
+++ b/doc/cmd/redo-ifchange
@@ -8,6 +8,8 @@ Pay attention that redo-ifchange enables parallel builds of the given
 targets, but ordinary redo is not: it builds specified targets
 sequentially and stops when error happens.
 
+It will warn if non-top target did not write anything.
+
 A [Env] REDO_STOP_IF_MODIFIED
 If redo sees some target modified externally, then by default it warns
 user about that, does not build that target, but continues the build
diff --git a/run.go b/run.go
index 43ebcfefbfd8d60ccb54cd3451d5481b3518ca4281a0ff118d07e99bf2d71f57..8e8adb786c06537b34e0fc337e6928cac32217b88395c72d685ea8e1dbcde8bd 100644
--- a/run.go
+++ b/run.go
@@ -745,6 +745,9 @@ 		}
 
 		// Do we need to ifcreate it, or ifchange with renaming?
 		if fd == nil {
+			if Level > 0 {
+				tracef(CWarn, "%s: nothing written to target", tgt)
+			}
 			os.Remove(tgt.a)
 			err = ifcreate(fdDepW, fdDep.Name(), tgtT)
 			if err != nil {
diff --git a/t/goredo-build-uuid-for-fdood.t b/t/goredo-build-uuid-for-fdood.t
index 166cb5e65ee9b5f3baf306c6fe2e0f98c04ebaded5402ce8890b2174b9bdbfd3..275f48e04bafa8b56236650df1c0257b91ed4f22988607ef01fa93f180a22ad4 100755
--- a/t/goredo-build-uuid-for-fdood.t
+++ b/t/goredo-build-uuid-for-fdood.t
@@ -6,9 +6,12 @@ export REDO_TOP_DIR="`pwd`" REDO_NO_PROGRESS=1
 
 echo redo-ifchange l3 l2 >l1.do
 echo redo-ifchange l3 >l2.do
+echo echo ok >>l1.do
+echo echo ok >>l2.do
 cat >l3.do <<EOF
 sleep 1
 touch \$(date +%s).touch
+echo ok
 EOF
 
 redo -j 1 l1
diff --git a/t/goredo-double-consideration.t b/t/goredo-double-consideration.t
index 2bc31d02d7cecb7e285e15924f2fcca0db7510e9805cf6d0a483377e24a62564..67a1c0894b51efd302743797b8607a32774af92399efde5dd1326de133e78d2c 100755
--- a/t/goredo-double-consideration.t
+++ b/t/goredo-double-consideration.t
@@ -4,7 +4,10 @@ test_description="Do not fail if two always-ed targets run simultaneously"
 . $SHARNESS_TEST_SRCDIR/sharness.sh
 export REDO_TOP_DIR="`pwd`" REDO_NO_PROGRESS=1
 
-echo redo-ifchange version.h >all.do
+cat >all.do <<EOF
+redo-ifchange version.h
+echo ok
+EOF
 cat >version.h.do <<EOF
 redo-ifchange date version version.h.in
 VERSION=\$(cat version)
diff --git a/t/redo-sh.tests/nothing_written_1/test b/t/redo-sh.tests/nothing_written_1/test
new file mode 100755
index 0000000000000000000000000000000000000000..8049cf9c4d0af9dcd0a1da186a94ef477e2fa1f02c24b6ee35acf26899429611
--- /dev/null
+++ b/t/redo-sh.tests/nothing_written_1/test
@@ -0,0 +1,10 @@
+#!/bin/sh -eu
+# A non-top-level build rule not writing to a target must yield a warning.
+
+>all.do printf 'redo-ifchange a
+'
+
+>a.do :
+
+2>stderr redo
+<stderr grep -q 'a: nothing written to target'
diff --git a/t/redo-sh.tests/nothing_written_2/test b/t/redo-sh.tests/nothing_written_2/test
new file mode 100755
index 0000000000000000000000000000000000000000..3e7cd22f07fea73c34985105d5d28fdde78052cecaab6a64ba95561404c6b27f
--- /dev/null
+++ b/t/redo-sh.tests/nothing_written_2/test
@@ -0,0 +1,14 @@
+#!/bin/sh -eu
+# Each non-top-level build rule not writing to a target must yield a warning.
+
+>all.do printf 'redo-ifchange a
+'
+
+>a.do printf 'redo-ifchange b
+'
+
+>b.do :
+
+2>stderr redo
+<stderr grep -q 'a: nothing written to target'
+<stderr grep -q 'b: nothing written to target'
diff --git a/t/redo-sh.tests/parallel_1/test b/t/redo-sh.tests/parallel_1/test
index 700d4f186f5d5450c207fcdac771a01b271f9333c4aa60e0a323f16daef1d88b..d9c594463f2e462cf5d80d67124addbb5034dd9ca9804abb2d0ea246275b4adb 100755
--- a/t/redo-sh.tests/parallel_1/test
+++ b/t/redo-sh.tests/parallel_1/test
@@ -10,6 +10,7 @@ EOF
 
 >default.do cat <<EOF
 redo-always
+date +%s
 sleep 1
 EOF
 
diff --git a/t/redosh-nothing_written_1.t b/t/redosh-nothing_written_1.t
new file mode 120000
index 0000000000000000000000000000000000000000..8630ce5b04c2446d2bc2f6b421d0110def671d254125aa2a09a8553ecb4b66d8
--- /dev/null
+++ b/t/redosh-nothing_written_1.t
@@ -0,0 +1 @@
+redo-sh.tests/wrapper.rc
\ No newline at end of file
diff --git a/t/redosh-nothing_written_2.t b/t/redosh-nothing_written_2.t
new file mode 120000
index 0000000000000000000000000000000000000000..8630ce5b04c2446d2bc2f6b421d0110def671d254125aa2a09a8553ecb4b66d8
--- /dev/null
+++ b/t/redosh-nothing_written_2.t
@@ -0,0 +1 @@
+redo-sh.tests/wrapper.rc
\ No newline at end of file
diff --git a/usage.go b/usage.go
index 7c2bf5000d037d8649e249ee4171da538740e0adbc08743834531fbcdafd3a42..0681395e71ac8f7bb2da37b871efdf937a3f8665584d24c3df59b2c32fdee932 100644
--- a/usage.go
+++ b/usage.go
@@ -24,7 +24,7 @@ 	"strings"
 )
 
 const (
-	Version  = "2.8.1"
+	Version  = "2.9.0"
 	Warranty = `Copyright (C) 2020-2026 Sergey Matveev
 
 This program is free software: you can redistribute it and/or modify