diff --git a/context.go b/context.go
index 9e72fd0b..2af7101f 100644
--- a/context.go
+++ b/context.go
@@ -587,7 +587,7 @@ func (c *context) contain(p string) (string, error) {
 
 	// ZOMBIES(stevvooe): In certain cases, we may want to remap these to a
 	// "containment error", so the caller can decide what to do.
-	return filepath.Join("/", filepath.Clean(sanitized)), nil
+	return filepath.Clean(sanitized), nil
 }
 
 // digest returns the digest of the file at path p, relative to the root.
diff --git a/manifest.go b/manifest.go
index 20706f35..55fbcfb5 100644
--- a/manifest.go
+++ b/manifest.go
@@ -66,7 +66,7 @@ func BuildManifest(ctx Context) (*Manifest, error) {
 			return fmt.Errorf("error walking %s: %v", p, err)
 		}
 
-		if p == "/" {
+		if p == "." {
 			// skip root
 			return nil
 		}
diff --git a/manifest_test.go b/manifest_test.go
index 5abe6043..680f271f 100644
--- a/manifest_test.go
+++ b/manifest_test.go
@@ -113,7 +113,7 @@ func TestWalkFS(t *testing.T) {
 
 		{
 			kind: rdirectory,
-			path: "/dev",
+			path: "dev",
 			mode: 0755,
 		},
 
@@ -311,15 +311,14 @@ func expectedResourceList(root string, resources []dresource) ([]Resource, error
 	resourceMap := map[string]Resource{}
 	paths := []string{}
 	for _, r := range resources {
-		absPath := r.path
-		if !filepath.IsAbs(absPath) {
-			absPath = "/" + absPath
+		if filepath.IsAbs(r.path) {
+			return nil, fmt.Errorf("path must be relative: %q", r.path)
 		}
 		switch r.kind {
 		case rfile:
 			f := &regularFile{
 				resource: resource{
-					paths: []string{absPath},
+					paths: []string{r.path},
 					mode:  r.mode,
 					uid:   r.uid,
 					gid:   r.gid,
@@ -327,25 +326,24 @@ func expectedResourceList(root string, resources []dresource) ([]Resource, error
 				size:    int64(r.size),
 				digests: []digest.Digest{r.digest},
 			}
-			resourceMap[absPath] = f
-			paths = append(paths, absPath)
+			resourceMap[r.path] = f
+			paths = append(paths, r.path)
 		case rdirectory:
 			d := &directory{
 				resource: resource{
-					paths: []string{absPath},
+					paths: []string{r.path},
 					mode:  r.mode,
 					uid:   r.uid,
 					gid:   r.gid,
 				},
 			}
-			resourceMap[absPath] = d
-			paths = append(paths, absPath)
+			resourceMap[r.path] = d
+			paths = append(paths, r.path)
 		case rhardlink:
-			targetPath := r.target
-			if !filepath.IsAbs(targetPath) {
-				targetPath = "/" + targetPath
+			if filepath.IsAbs(r.target) {
+				return nil, fmt.Errorf("target must be relative: %q", r.target)
 			}
-			target, ok := resourceMap[targetPath]
+			target, ok := resourceMap[r.target]
 			if !ok {
 				return nil, errors.New("must specify target before hardlink for test resources")
 			}
@@ -354,7 +352,7 @@ func expectedResourceList(root string, resources []dresource) ([]Resource, error
 				return nil, errors.New("hardlink target must be regular file")
 			}
 			// TODO(dmcgowan): full merge
-			rf.paths = append(rf.paths, absPath)
+			rf.paths = append(rf.paths, r.path)
 			// TODO(dmcgowan): check if first path is now different, changes source order and should update
 			// resource map key, to avoid canonically ordered first should be regular file
 			sort.Stable(sort.StringSlice(rf.paths))
@@ -366,19 +364,19 @@ func expectedResourceList(root string, resources []dresource) ([]Resource, error
 			}
 			s := &symLink{
 				resource: resource{
-					paths: []string{absPath},
+					paths: []string{r.path},
 					mode:  r.mode,
 					uid:   r.uid,
 					gid:   r.gid,
 				},
 				target: targetPath,
 			}
-			resourceMap[absPath] = s
-			paths = append(paths, absPath)
+			resourceMap[r.path] = s
+			paths = append(paths, r.path)
 		case rchardev:
 			d := &device{
 				resource: resource{
-					paths: []string{absPath},
+					paths: []string{r.path},
 					mode:  r.mode,
 					uid:   r.uid,
 					gid:   r.gid,
@@ -386,19 +384,19 @@ func expectedResourceList(root string, resources []dresource) ([]Resource, error
 				major: uint64(r.major),
 				minor: uint64(r.minor),
 			}
-			resourceMap[absPath] = d
-			paths = append(paths, absPath)
+			resourceMap[r.path] = d
+			paths = append(paths, r.path)
 		case rnamedpipe:
 			p := &namedPipe{
 				resource: resource{
-					paths: []string{absPath},
+					paths: []string{r.path},
 					mode:  r.mode,
 					uid:   r.uid,
 					gid:   r.gid,
 				},
 			}
-			resourceMap[absPath] = p
-			paths = append(paths, absPath)
+			resourceMap[r.path] = p
+			paths = append(paths, r.path)
 		default:
 			return nil, fmt.Errorf("unknown resource type: %v", r.kind)
 		}
diff --git a/manifest_test_darwin.go b/manifest_test_darwin.go
index 873ec318..c90e8bf8 100644
--- a/manifest_test_darwin.go
+++ b/manifest_test_darwin.go
@@ -7,7 +7,7 @@ import "os"
 var (
 	devNullResource = resource{
 		kind:  chardev,
-		path:  "/dev/null",
+		path:  "dev/null",
 		major: 3,
 		minor: 2,
 		mode:  0666 | os.ModeDevice | os.ModeCharDevice,
@@ -15,7 +15,7 @@ var (
 
 	devZeroResource = resource{
 		kind:  chardev,
-		path:  "/dev/zero",
+		path:  "dev/zero",
 		major: 3,
 		minor: 3,
 		mode:  0666 | os.ModeDevice | os.ModeCharDevice,
diff --git a/proto/manifest.pb.go b/proto/manifest.pb.go
index 05107c1d..b8a10167 100644
--- a/proto/manifest.pb.go
+++ b/proto/manifest.pb.go
@@ -52,7 +52,9 @@ func (m *Manifest) GetResource() []*Resource {
 type Resource struct {
 	// Path specifies the path from the bundle root. If more than one
 	// path is present, the entry may represent a hardlink, rather than using
-	// a link target. The path format is operating system specific.
+	// a link target.
+	// A path must be relative to the bundle root.
+	// TODO(AkihiroSuda): use '/' seperator regardless of the operating system used for building the manifest?
 	Path []string `protobuf:"bytes,1,rep,name=path" json:"path,omitempty"`
 	// Uid specifies the user id for the resource.
 	Uid int64 `protobuf:"varint,2,opt,name=uid" json:"uid,omitempty"`
diff --git a/proto/manifest.proto b/proto/manifest.proto
index 844ea791..f4bbd51d 100644
--- a/proto/manifest.proto
+++ b/proto/manifest.proto
@@ -11,7 +11,9 @@ message Manifest {
 message Resource {
     // Path specifies the path from the bundle root. If more than one
     // path is present, the entry may represent a hardlink, rather than using
-    // a link target. The path format is operating system specific.
+    // a link target.
+    // A path must be relative to the bundle root.
+    // TODO(AkihiroSuda): use '/' seperator regardless of the operating system used for building the manifest?
     repeated string path = 1;
 
     // NOTE(stevvooe): Need to define clear precedence for user/group/uid/gid precedence.