diff --git a/bootstrap.bash b/bootstrap.bash
index 08b85b5..b08bf1e 100755
--- a/bootstrap.bash
+++ b/bootstrap.bash
@@ -67,12 +67,14 @@ usage() {
     echo "  -h: print a help message and exit"
     echo "  -b <builddir>: set the build directory"
     echo "  -t: run tests"
+    echo "  -n: use validations to depend on tests"
 }
 
 # Parse the command line flags.
-while getopts ":b:ht" opt; do
+while getopts ":b:hnt" opt; do
     case $opt in
         b) BUILDDIR="$OPTARG";;
+        n) USE_VALIDATIONS=true;;
         t) RUN_TESTS=true;;
         h)
             usage
@@ -93,6 +95,9 @@ done
 # If RUN_TESTS is set, behave like -t was passed in as an option.
 [ ! -z "$RUN_TESTS" ] && EXTRA_ARGS="${EXTRA_ARGS} -t"
 
+# If $USE_VALIDATIONS is set, pass --use-validations.
+[ ! -z "$USE_VALIDATIONS" ] && EXTRA_ARGS="${EXTRA_ARGS} --use-validations"
+
 # If EMPTY_NINJA_FILE is set, have the primary build write out a 0-byte ninja
 # file instead of a full length one. Useful if you don't plan on executing the
 # build, but want to verify the primary builder execution.
diff --git a/bootstrap/bootstrap.go b/bootstrap/bootstrap.go
index bb85e7d..8a9a5f8 100644
--- a/bootstrap/bootstrap.go
+++ b/bootstrap/bootstrap.go
@@ -338,7 +338,7 @@ func (g *goPackage) GenerateBuildActions(ctx blueprint.ModuleContext) {
 			filepath.FromSlash(g.properties.PkgPath)+".a")
 		g.testResultFile = buildGoTest(ctx, testRoot(ctx, g.config), testArchiveFile,
 			g.properties.PkgPath, srcs, genSrcs,
-			testSrcs)
+			testSrcs, g.config.useValidations)
 	}
 
 	buildGoPackage(ctx, g.pkgRoot, g.properties.PkgPath, g.archiveFile,
@@ -421,7 +421,7 @@ func (g *goBinary) GenerateBuildActions(ctx blueprint.ModuleContext) {
 		genSrcs = append(genSrcs, pluginSrc)
 	}
 
-	var deps []string
+	var testDeps []string
 
 	if hasPlugins && !buildGoPluginLoader(ctx, "main", pluginSrc) {
 		return
@@ -437,8 +437,8 @@ func (g *goBinary) GenerateBuildActions(ctx blueprint.ModuleContext) {
 	}
 
 	if g.config.runGoTests {
-		deps = buildGoTest(ctx, testRoot(ctx, g.config), testArchiveFile,
-			name, srcs, genSrcs, testSrcs)
+		testDeps = buildGoTest(ctx, testRoot(ctx, g.config), testArchiveFile,
+			name, srcs, genSrcs, testSrcs, g.config.useValidations)
 	}
 
 	buildGoPackage(ctx, objDir, "main", archiveFile, srcs, genSrcs)
@@ -451,7 +451,7 @@ func (g *goBinary) GenerateBuildActions(ctx blueprint.ModuleContext) {
 			linkDeps = append(linkDeps, dep.GoPackageTarget())
 			libDir := dep.GoPkgRoot()
 			libDirFlags = append(libDirFlags, "-L "+libDir)
-			deps = append(deps, dep.GoTestTargets()...)
+			testDeps = append(testDeps, dep.GoTestTargets()...)
 		})
 
 	linkArgs := map[string]string{}
@@ -468,12 +468,20 @@ func (g *goBinary) GenerateBuildActions(ctx blueprint.ModuleContext) {
 		Optional:  true,
 	})
 
+	var orderOnlyDeps, validationDeps []string
+	if g.config.useValidations {
+		validationDeps = testDeps
+	} else {
+		orderOnlyDeps = testDeps
+	}
+
 	ctx.Build(pctx, blueprint.BuildParams{
-		Rule:      cp,
-		Outputs:   []string{g.installPath},
-		Inputs:    []string{aoutFile},
-		OrderOnly: deps,
-		Optional:  !g.properties.Default,
+		Rule:        cp,
+		Outputs:     []string{g.installPath},
+		Inputs:      []string{aoutFile},
+		OrderOnly:   orderOnlyDeps,
+		Validations: validationDeps,
+		Optional:    !g.properties.Default,
 	})
 }
 
@@ -538,7 +546,7 @@ func buildGoPackage(ctx blueprint.ModuleContext, pkgRoot string,
 }
 
 func buildGoTest(ctx blueprint.ModuleContext, testRoot, testPkgArchive,
-	pkgPath string, srcs, genSrcs, testSrcs []string) []string {
+	pkgPath string, srcs, genSrcs, testSrcs []string, useValidations bool) []string {
 
 	if len(testSrcs) == 0 {
 		return nil
@@ -600,11 +608,19 @@ func buildGoTest(ctx blueprint.ModuleContext, testRoot, testPkgArchive,
 		Optional: true,
 	})
 
+	var orderOnlyDeps, validationDeps []string
+	if useValidations {
+		validationDeps = testDeps
+	} else {
+		orderOnlyDeps = testDeps
+	}
+
 	ctx.Build(pctx, blueprint.BuildParams{
-		Rule:      test,
-		Outputs:   []string{testPassed},
-		Inputs:    []string{testFile},
-		OrderOnly: testDeps,
+		Rule:        test,
+		Outputs:     []string{testPassed},
+		Inputs:      []string{testFile},
+		OrderOnly:   orderOnlyDeps,
+		Validations: validationDeps,
 		Args: map[string]string{
 			"pkg":       pkgPath,
 			"pkgSrcDir": filepath.Dir(testFiles[0]),
diff --git a/bootstrap/command.go b/bootstrap/command.go
index 1f73ce3..dc655e8 100644
--- a/bootstrap/command.go
+++ b/bootstrap/command.go
@@ -40,6 +40,7 @@ var (
 	memprofile     string
 	traceFile      string
 	runGoTests     bool
+	useValidations bool
 	noGC           bool
 	emptyNinjaFile bool
 	BuildDir       string
@@ -61,6 +62,7 @@ func init() {
 	flag.StringVar(&memprofile, "memprofile", "", "write memory profile to file")
 	flag.BoolVar(&noGC, "nogc", false, "turn off GC for debugging")
 	flag.BoolVar(&runGoTests, "t", false, "build and run go tests during bootstrap")
+	flag.BoolVar(&useValidations, "use-validations", false, "use validations to depend on go tests")
 	flag.StringVar(&ModuleListFile, "l", "", "file that lists filepaths to parse")
 	flag.BoolVar(&emptyNinjaFile, "empty-ninja-file", false, "write out a 0-byte ninja file")
 }
@@ -131,6 +133,7 @@ func Main(ctx *blueprint.Context, config interface{}, extraNinjaFileDeps ...stri
 		topLevelBlueprintsFile: flag.Arg(0),
 		emptyNinjaFile:         emptyNinjaFile,
 		runGoTests:             runGoTests,
+		useValidations:         useValidations,
 		moduleListFile:         ModuleListFile,
 	}
 
diff --git a/bootstrap/config.go b/bootstrap/config.go
index 9499aeb..ace0ae6 100644
--- a/bootstrap/config.go
+++ b/bootstrap/config.go
@@ -107,5 +107,6 @@ type Config struct {
 
 	emptyNinjaFile bool
 	runGoTests     bool
+	useValidations bool
 	moduleListFile string
 }
diff --git a/live_tracker.go b/live_tracker.go
index 40e1930..1d48e58 100644
--- a/live_tracker.go
+++ b/live_tracker.go
@@ -68,6 +68,11 @@ func (l *liveTracker) AddBuildDefDeps(def *buildDef) error {
 		return err
 	}
 
+	err = l.addNinjaStringListDeps(def.Validations)
+	if err != nil {
+		return err
+	}
+
 	for _, value := range def.Variables {
 		err = l.addNinjaStringDeps(value)
 		if err != nil {
diff --git a/ninja_defs.go b/ninja_defs.go
index c5d0e4b..8c5db57 100644
--- a/ninja_defs.go
+++ b/ninja_defs.go
@@ -87,6 +87,7 @@ type BuildParams struct {
 	Inputs          []string          // The list of explicit input dependencies.
 	Implicits       []string          // The list of implicit input dependencies.
 	OrderOnly       []string          // The list of order-only dependencies.
+	Validations     []string          // The list of validations to run when this rule runs.
 	Args            map[string]string // The variable/value pairs to set.
 	Optional        bool              // Skip outputting a default statement
 }
@@ -257,6 +258,7 @@ type buildDef struct {
 	Inputs          []ninjaString
 	Implicits       []ninjaString
 	OrderOnly       []ninjaString
+	Validations     []ninjaString
 	Args            map[Variable]ninjaString
 	Variables       map[string]ninjaString
 	Optional        bool
@@ -314,6 +316,11 @@ func parseBuildParams(scope scope, params *BuildParams) (*buildDef,
 		return nil, fmt.Errorf("error parsing OrderOnly param: %s", err)
 	}
 
+	b.Validations, err = parseNinjaStrings(scope, params.Validations)
+	if err != nil {
+		return nil, fmt.Errorf("error parsing Validations param: %s", err)
+	}
+
 	b.Optional = params.Optional
 
 	if params.Depfile != "" {
@@ -373,6 +380,7 @@ func (b *buildDef) WriteTo(nw *ninjaWriter, pkgNames map[*packageContext]string)
 		explicitDeps  = valueList(b.Inputs, pkgNames, inputEscaper)
 		implicitDeps  = valueList(b.Implicits, pkgNames, inputEscaper)
 		orderOnlyDeps = valueList(b.OrderOnly, pkgNames, inputEscaper)
+		validations   = valueList(b.Validations, pkgNames, inputEscaper)
 	)
 
 	if b.RuleDef != nil {
@@ -380,7 +388,7 @@ func (b *buildDef) WriteTo(nw *ninjaWriter, pkgNames map[*packageContext]string)
 		orderOnlyDeps = append(valueList(b.RuleDef.CommandOrderOnly, pkgNames, inputEscaper), orderOnlyDeps...)
 	}
 
-	err := nw.Build(comment, rule, outputs, implicitOuts, explicitDeps, implicitDeps, orderOnlyDeps)
+	err := nw.Build(comment, rule, outputs, implicitOuts, explicitDeps, implicitDeps, orderOnlyDeps, validations)
 	if err != nil {
 		return err
 	}
diff --git a/ninja_writer.go b/ninja_writer.go
index 5366f3f..5e69c08 100644
--- a/ninja_writer.go
+++ b/ninja_writer.go
@@ -104,7 +104,7 @@ func (n *ninjaWriter) Rule(name string) error {
 }
 
 func (n *ninjaWriter) Build(comment string, rule string, outputs, implicitOuts,
-	explicitDeps, implicitDeps, orderOnlyDeps []string) error {
+	explicitDeps, implicitDeps, orderOnlyDeps, validations []string) error {
 
 	n.justDidBlankLine = false
 
@@ -161,6 +161,14 @@ func (n *ninjaWriter) Build(comment string, rule string, outputs, implicitOuts,
 		}
 	}
 
+	if len(validations) > 0 {
+		wrapper.WriteStringWithSpace("|@")
+
+		for _, dep := range validations {
+			wrapper.WriteStringWithSpace(dep)
+		}
+	}
+
 	return wrapper.Flush()
 }
 
diff --git a/ninja_writer_test.go b/ninja_writer_test.go
index cc880e5..48ecb7c 100644
--- a/ninja_writer_test.go
+++ b/ninja_writer_test.go
@@ -50,9 +50,9 @@ var ninjaWriterTestCases = []struct {
 	{
 		input: func(w *ninjaWriter) {
 			ck(w.Build("foo comment", "foo", []string{"o1", "o2"}, []string{"io1", "io2"},
-				[]string{"e1", "e2"}, []string{"i1", "i2"}, []string{"oo1", "oo2"}))
+				[]string{"e1", "e2"}, []string{"i1", "i2"}, []string{"oo1", "oo2"}, []string{"v1", "v2"}))
 		},
-		output: "# foo comment\nbuild o1 o2 | io1 io2: foo e1 e2 | i1 i2 || oo1 oo2\n",
+		output: "# foo comment\nbuild o1 o2 | io1 io2: foo e1 e2 | i1 i2 || oo1 oo2 |@ v1 v2\n",
 	},
 	{
 		input: func(w *ninjaWriter) {
@@ -94,7 +94,7 @@ var ninjaWriterTestCases = []struct {
 			ck(w.ScopedAssign("command", "echo out: $out in: $in _arg: $_arg"))
 			ck(w.ScopedAssign("pool", "p"))
 			ck(w.BlankLine())
-			ck(w.Build("r comment", "r", []string{"foo.o"}, nil, []string{"foo.in"}, nil, nil))
+			ck(w.Build("r comment", "r", []string{"foo.o"}, nil, []string{"foo.in"}, nil, nil, nil))
 			ck(w.ScopedAssign("_arg", "arg value"))
 		},
 		output: `pool p