diff --git a/builder/dockerfile/dispatchers_unix.go b/builder/dockerfile/dispatchers_unix.go
index ba8e1d9053..d69e184220 100644
--- a/builder/dockerfile/dispatchers_unix.go
+++ b/builder/dockerfile/dispatchers_unix.go
@@ -22,7 +22,7 @@ func normalizeWorkdir(_ string, current string, requested string) (string, error
 	if !filepath.IsAbs(requested) {
 		return filepath.Join(string(os.PathSeparator), current, requested), nil
 	}
-	return requested, nil
+	return filepath.Clean(requested), nil
 }
 
 // resolveCmdLine takes a command line arg set and optionally prepends a platform-specific
diff --git a/integration-cli/docker_cli_build_test.go b/integration-cli/docker_cli_build_test.go
index 858d496b40..05f9e4b8af 100644
--- a/integration-cli/docker_cli_build_test.go
+++ b/integration-cli/docker_cli_build_test.go
@@ -4296,7 +4296,7 @@ func (s *DockerCLIBuildSuite) TestBuildBuildTimeArgExpansion(c *testing.T) {
 	imgName := "bldvarstest"
 
 	wdVar := "WDIR"
-	wdVal := "/tmp/"
+	wdVal := "/tmp"
 	addVar := "AFILE"
 	addVal := "addFile"
 	copyVar := "CFILE"