diff --git a/docs/api/v2/descriptors.go b/docs/api/v2/descriptors.go
index 5f091bbc9..73f8b463e 100644
--- a/docs/api/v2/descriptors.go
+++ b/docs/api/v2/descriptors.go
@@ -28,7 +28,7 @@ var (
 		Name:        "uuid",
 		Type:        "opaque",
 		Required:    true,
-		Description: `A uuid identifying the upload. This field can accept almost anything.`,
+		Description: "A uuid identifying the upload. This field can accept characters that match `[a-zA-Z0-9-_.=]+`.",
 	}
 
 	digestPathParameter = ParameterDescriptor{
@@ -985,7 +985,7 @@ var routeDescriptors = []RouteDescriptor{
 
 	{
 		Name:        RouteNameBlobUploadChunk,
-		Path:        "/v2/{name:" + RepositoryNameRegexp.String() + "}/blobs/uploads/{uuid}",
+		Path:        "/v2/{name:" + RepositoryNameRegexp.String() + "}/blobs/uploads/{uuid:[a-zA-Z0-9-_.=]+}",
 		Entity:      "Blob Upload",
 		Description: "Interact with blob uploads. Clients should never assemble URLs for this endpoint and should only take it through the `Location` header on related API requests. The `Location` header and its parameters should be preserved by clients, using the latest value returned via upload related API calls.",
 		Methods: []MethodDescriptor{
diff --git a/docs/api/v2/routes_test.go b/docs/api/v2/routes_test.go
index afab71fce..fb268336f 100644
--- a/docs/api/v2/routes_test.go
+++ b/docs/api/v2/routes_test.go
@@ -98,6 +98,7 @@ func TestRouter(t *testing.T) {
 			},
 		},
 		{
+			// support uuid proper
 			RouteName:  RouteNameBlobUploadChunk,
 			RequestURI: "/v2/foo/bar/blobs/uploads/D95306FA-FAD3-4E36-8D41-CF1C93EF8286",
 			Vars: map[string]string{
@@ -113,6 +114,21 @@ func TestRouter(t *testing.T) {
 				"uuid": "RDk1MzA2RkEtRkFEMy00RTM2LThENDEtQ0YxQzkzRUY4Mjg2IA==",
 			},
 		},
+		{
+			// supports urlsafe base64
+			RouteName:  RouteNameBlobUploadChunk,
+			RequestURI: "/v2/foo/bar/blobs/uploads/RDk1MzA2RkEtRkFEMy00RTM2LThENDEtQ0YxQzkzRUY4Mjg2IA_-==",
+			Vars: map[string]string{
+				"name": "foo/bar",
+				"uuid": "RDk1MzA2RkEtRkFEMy00RTM2LThENDEtQ0YxQzkzRUY4Mjg2IA_-==",
+			},
+		},
+		{
+			// does not match
+			RouteName:  RouteNameBlobUploadChunk,
+			RequestURI: "/v2/foo/bar/blobs/uploads/totalandcompletejunk++$$-==",
+			StatusCode: http.StatusNotFound,
+		},
 		{
 			// Check ambiguity: ensure we can distinguish between tags for
 			// "foo/bar/image/image" and image for "foo/bar/image" with tag