diff --git a/builder/parser/line_parsers.go b/builder/parser/line_parsers.go
index 9bea21a958..b28693666c 100644
--- a/builder/parser/line_parsers.go
+++ b/builder/parser/line_parsers.go
@@ -232,6 +232,11 @@ func parseString(rest string) (*Node, map[string]bool, error) {
 
 // parseJSON converts JSON arrays to an AST.
 func parseJSON(rest string) (*Node, map[string]bool, error) {
+	rest = strings.TrimLeftFunc(rest, unicode.IsSpace)
+	if !strings.HasPrefix(rest, "[") {
+		return nil, nil, fmt.Errorf(`Error parsing "%s" as a JSON array`, rest)
+	}
+
 	var myJSON []interface{}
 	if err := json.NewDecoder(strings.NewReader(rest)).Decode(&myJSON); err != nil {
 		return nil, nil, err
diff --git a/builder/parser/testfiles/ADD-COPY-with-JSON/Dockerfile b/builder/parser/testfiles/ADD-COPY-with-JSON/Dockerfile
index 49372b0607..00b444cba5 100644
--- a/builder/parser/testfiles/ADD-COPY-with-JSON/Dockerfile
+++ b/builder/parser/testfiles/ADD-COPY-with-JSON/Dockerfile
@@ -3,6 +3,8 @@ MAINTAINER	Seongyeol Lim <seongyeol37@gmail.com>
 
 COPY	.	/go/src/github.com/docker/docker
 ADD		.	/
+ADD		null /
+COPY	nullfile /tmp
 ADD		[ "vimrc", "/tmp" ]
 COPY	[ "bashrc", "/tmp" ]
 COPY	[ "test file", "/tmp" ]
diff --git a/builder/parser/testfiles/ADD-COPY-with-JSON/result b/builder/parser/testfiles/ADD-COPY-with-JSON/result
index 86c3fef726..85aee64018 100644
--- a/builder/parser/testfiles/ADD-COPY-with-JSON/result
+++ b/builder/parser/testfiles/ADD-COPY-with-JSON/result
@@ -2,6 +2,8 @@
 (maintainer "Seongyeol Lim <seongyeol37@gmail.com>")
 (copy "." "/go/src/github.com/docker/docker")
 (add "." "/")
+(add "null" "/")
+(copy "nullfile" "/tmp")
 (add "vimrc" "/tmp")
 (copy "bashrc" "/tmp")
 (copy "test file" "/tmp")
diff --git a/integration-cli/docker_cli_build_test.go b/integration-cli/docker_cli_build_test.go
index dad833ac42..bf7de304c5 100644
--- a/integration-cli/docker_cli_build_test.go
+++ b/integration-cli/docker_cli_build_test.go
@@ -5444,3 +5444,26 @@ func (s *DockerTrustSuite) TestBuildContextDirIsSymlink(c *check.C) {
 		c.Fatalf("build failed with exit status %d: %s", exitStatus, out)
 	}
 }
+
+// Issue #15634: COPY fails when path starts with "null"
+func (s *DockerSuite) TestBuildNullStringInAddCopyVolume(c *check.C) {
+	name := "testbuildnullstringinaddcopyvolume"
+
+	ctx, err := fakeContext(`
+		FROM busybox
+		
+		ADD null /
+		COPY nullfile /
+		VOLUME nullvolume
+		`,
+		map[string]string{
+			"null":     "test1",
+			"nullfile": "test2",
+		},
+	)
+	defer ctx.Close()
+	c.Assert(err, check.IsNil)
+
+	_, err = buildImageFromContext(name, ctx, true)
+	c.Assert(err, check.IsNil)
+}