diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 5a73adf..0ef96fb 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -14,6 +14,11 @@ jobs:
         go-version: ${{ matrix.go-version }}
     - name: Checkout code
       uses: actions/checkout@v4
+    -  run: |
+          if [ "${{ matrix.go-version }}" = "1.18.x" ]; then
+            # Skip userns on go1.18.x
+            echo 'PACKAGES="mountinfo mount sequential signal symlink user"' >> $GITHUB_ENV
+          fi
     - name: go mod tidy
       run: |
         make tidy
diff --git a/Makefile b/Makefile
index c83bf16..50ce9e5 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-PACKAGES ?= mountinfo mount sequential signal symlink user
+PACKAGES ?= mountinfo mount sequential signal symlink user userns
 BINDIR ?= _build/bin
 CROSS ?= linux/arm linux/arm64 linux/ppc64le linux/s390x \
 	freebsd/amd64 openbsd/amd64 darwin/amd64 darwin/arm64 windows/amd64
@@ -16,18 +16,14 @@ clean:
 test: test-local
 	set -eu; \
 	for p in $(PACKAGES); do \
-		if $p = user && go version | grep -qv go1.18; then \
-			(cd $$p; go test $(RUN_VIA_SUDO) -v .); \
-		fi \
+		(cd $$p; go test $(RUN_VIA_SUDO) -v .); \
 	done
 
 .PHONY: tidy
 tidy:
 	set -eu; \
 	for p in $(PACKAGES); do \
-		if $p = user && go version | grep -qv go1.18; then \
-			(cd $$p; go mod tidy); \
-		fi \
+		(cd $$p; go mod tidy); \
 	done
 
 # Test the mount module against the local mountinfo source code instead of the
@@ -46,11 +42,9 @@ lint: $(BINDIR)/golangci-lint
 	$(BINDIR)/golangci-lint version
 	set -eu; \
 	for p in $(PACKAGES); do \
-		if $p = user && go version | grep -qv go1.18; then \
-			(cd $$p; \
-			go mod download; \
-			../$(BINDIR)/golangci-lint run); \
-		fi \
+		(cd $$p; \
+		go mod download; \
+		../$(BINDIR)/golangci-lint run); \
 	done
 
 $(BINDIR)/golangci-lint: $(BINDIR)
diff --git a/user/go.mod b/user/go.mod
index d4ad72f..bf7886e 100644
--- a/user/go.mod
+++ b/user/go.mod
@@ -1,5 +1,7 @@
 module github.com/moby/sys/user
 
-go 1.21
+go 1.17
 
 require golang.org/x/sys v0.1.0
+
+retract v0.2.0 // Package github.com/moby/sys/user/userns was included in this module, but should've been a separate module; see https://github.com/moby/sys/pull/140#issuecomment-2250644304.
diff --git a/userns/go.mod b/userns/go.mod
new file mode 100644
index 0000000..1b656e4
--- /dev/null
+++ b/userns/go.mod
@@ -0,0 +1,3 @@
+module github.com/moby/sys/userns
+
+go 1.21
diff --git a/user/userns/userns.go b/userns/userns.go
similarity index 100%
rename from user/userns/userns.go
rename to userns/userns.go
diff --git a/user/userns/userns_linux.go b/userns/userns_linux.go
similarity index 100%
rename from user/userns/userns_linux.go
rename to userns/userns_linux.go
diff --git a/user/userns/userns_linux_fuzzer.go b/userns/userns_linux_fuzzer.go
similarity index 100%
rename from user/userns/userns_linux_fuzzer.go
rename to userns/userns_linux_fuzzer.go
diff --git a/user/userns/userns_linux_test.go b/userns/userns_linux_test.go
similarity index 100%
rename from user/userns/userns_linux_test.go
rename to userns/userns_linux_test.go
diff --git a/user/userns/userns_unsupported.go b/userns/userns_unsupported.go
similarity index 100%
rename from user/userns/userns_unsupported.go
rename to userns/userns_unsupported.go