diff --git a/ctl/import_test.go b/ctl/import_test.go
index ba8a9dc6e..2284ca873 100644
--- a/ctl/import_test.go
+++ b/ctl/import_test.go
@@ -183,6 +183,7 @@ func TestImportCommand_InvalidFile(t *testing.T) {
 // MustNewHTTPRequest creates a new HTTP request. Panic on error.
 func MustNewHTTPRequest(method, urlStr string, body io.Reader) *http.Request {
 	req, err := http.NewRequest(method, urlStr, body)
+	req.Header.Add("Accept", "application/json")
 	if err != nil {
 		panic(err)
 	}
diff --git a/http/client.go b/http/client.go
index d8f0d290d..5090072a3 100644
--- a/http/client.go
+++ b/http/client.go
@@ -90,6 +90,7 @@ func (c *InternalClient) maxSliceByIndex(ctx context.Context) (map[string]uint64
 	}
 
 	req.Header.Set("User-Agent", "pilosa/"+pilosa.Version)
+	req.Header.Set("Accept", "application/json")
 
 	// Execute request.
 	resp, err := c.HTTPClient.Do(req.WithContext(ctx))
@@ -120,6 +121,7 @@ func (c *InternalClient) Schema(ctx context.Context) ([]*pilosa.IndexInfo, error
 	}
 
 	req.Header.Set("User-Agent", "pilosa/"+pilosa.Version)
+	req.Header.Set("Accept", "application/json")
 
 	// Execute request.
 	resp, err := c.HTTPClient.Do(req.WithContext(ctx))
@@ -195,6 +197,7 @@ func (c *InternalClient) FragmentNodes(ctx context.Context, index string, slice
 	}
 
 	req.Header.Set("User-Agent", "pilosa/"+pilosa.Version)
+	req.Header.Set("Accept", "application/json")
 
 	// Execute request.
 	resp, err := c.HTTPClient.Do(req.WithContext(ctx))
@@ -685,6 +688,7 @@ func (c *InternalClient) FragmentBlocks(ctx context.Context, uri *pilosa.URI, in
 	}
 
 	req.Header.Set("User-Agent", "pilosa/"+pilosa.Version)
+	req.Header.Set("Accept", "application/json")
 
 	// Execute request.
 	resp, err := c.HTTPClient.Do(req.WithContext(ctx))
@@ -777,6 +781,7 @@ func (c *InternalClient) ColumnAttrDiff(ctx context.Context, uri *pilosa.URI, in
 	}
 	req.Header.Set("Content-Type", "application/json")
 	req.Header.Set("User-Agent", "pilosa/"+pilosa.Version)
+	req.Header.Set("Accept", "application/json")
 
 	// Execute request.
 	resp, err := c.HTTPClient.Do(req.WithContext(ctx))
@@ -820,6 +825,7 @@ func (c *InternalClient) RowAttrDiff(ctx context.Context, uri *pilosa.URI, index
 	}
 	req.Header.Set("Content-Type", "application/json")
 	req.Header.Set("User-Agent", "pilosa/"+pilosa.Version)
+	req.Header.Set("Accept", "application/json")
 
 	// Execute request.
 	resp, err := c.HTTPClient.Do(req.WithContext(ctx))
@@ -859,6 +865,7 @@ func (c *InternalClient) SendMessage(ctx context.Context, uri *pilosa.URI, pb pr
 	}
 	req.Header.Set("Content-Type", "application/x-protobuf")
 	req.Header.Set("User-Agent", "pilosa/"+pilosa.Version)
+	req.Header.Set("Accept", "application/json")
 
 	// Execute request.
 	resp, err := c.HTTPClient.Do(req.WithContext(ctx))
diff --git a/http/handler.go b/http/handler.go
index 509378d6e..674381905 100644
--- a/http/handler.go
+++ b/http/handler.go
@@ -164,11 +164,12 @@ func (h *Handler) queryArgValidator(next http.Handler) http.Handler {
 func NewRouter(handler *Handler) *mux.Router {
 	router := mux.NewRouter()
 	router.HandleFunc("/", handler.handleHome).Methods("GET")
-	router.HandleFunc("/cluster/message", handler.handlePostClusterMessage).Methods("POST")
-	router.HandleFunc("/cluster/resize/set-coordinator", handler.handlePostClusterResizeSetCoordinator).Methods("POST")
 	router.PathPrefix("/debug/pprof/").Handler(http.DefaultServeMux).Methods("GET")
 	router.Handle("/debug/vars", expvar.Handler()).Methods("GET")
+
 	router.HandleFunc("/schema", handler.handleGetSchema).Methods("GET")
+	router.HandleFunc("/cluster/message", handler.handlePostClusterMessage).Methods("POST")
+	router.HandleFunc("/cluster/resize/set-coordinator", handler.handlePostClusterResizeSetCoordinator).Methods("POST")
 	router.HandleFunc("/slices/max", handler.handleGetSlicesMax).Methods("GET") // TODO: deprecate, but it's being used by the client
 	router.HandleFunc("/status", handler.handleGetStatus).Methods("GET")
 	router.HandleFunc("/info", handler.handleGetInfo).Methods("GET")
@@ -257,8 +258,28 @@ func (h *Handler) handleHome(w http.ResponseWriter, r *http.Request) {
 	http.Error(w, "Welcome. Pilosa is running. Visit https://www.pilosa.com/docs/ for more information.", http.StatusNotFound)
 }
 
+func checkHeaderAcceptJSON(header http.Header) bool {
+	v, found := header["Accept"]
+	sendError := false
+	if found {
+		sendError = true
+		for _, v := range v {
+			if v == "application/json" {
+				sendError = false
+
+			}
+		}
+	}
+	return sendError
+}
+
 // handleGetSchema handles GET /schema requests.
 func (h *Handler) handleGetSchema(w http.ResponseWriter, r *http.Request) {
+	if checkHeaderAcceptJSON(r.Header) {
+		http.Error(w, "JSON only acceptable response", http.StatusNotAcceptable)
+		return
+	}
+
 	schema := h.API.Schema(r.Context())
 	if err := json.NewEncoder(w).Encode(getSchemaResponse{
 		Indexes: schema,
@@ -269,6 +290,10 @@ func (h *Handler) handleGetSchema(w http.ResponseWriter, r *http.Request) {
 
 // handleGetStatus handles GET /status requests.
 func (h *Handler) handleGetStatus(w http.ResponseWriter, r *http.Request) {
+	if checkHeaderAcceptJSON(r.Header) {
+		http.Error(w, "JSON only acceptable response", http.StatusNotAcceptable)
+		return
+	}
 	status := getStatusResponse{
 		State:   h.API.State(),
 		Nodes:   h.API.Hosts(r.Context()),
@@ -280,6 +305,10 @@ func (h *Handler) handleGetStatus(w http.ResponseWriter, r *http.Request) {
 }
 
 func (h *Handler) handleGetInfo(w http.ResponseWriter, r *http.Request) {
+	if checkHeaderAcceptJSON(r.Header) {
+		http.Error(w, "JSON only acceptable response", http.StatusNotAcceptable)
+		return
+	}
 	info := h.API.Info()
 	if err := json.NewEncoder(w).Encode(info); err != nil {
 		h.Logger.Printf("write info response error: %s", err)
@@ -333,6 +362,10 @@ func (h *Handler) handlePostQuery(w http.ResponseWriter, r *http.Request) {
 
 // handleGetSlicesMax handles GET /schema requests.
 func (h *Handler) handleGetSlicesMax(w http.ResponseWriter, r *http.Request) {
+	if checkHeaderAcceptJSON(r.Header) {
+		http.Error(w, "JSON only acceptable response", http.StatusNotAcceptable)
+		return
+	}
 	if err := json.NewEncoder(w).Encode(getSlicesMaxResponse{
 		Standard: h.API.MaxSlices(r.Context()),
 	}); err != nil {
@@ -351,6 +384,10 @@ func (h *Handler) handleGetIndexes(w http.ResponseWriter, r *http.Request) {
 
 // handleGetIndex handles GET /index/<indexname> requests.
 func (h *Handler) handleGetIndex(w http.ResponseWriter, r *http.Request) {
+	if checkHeaderAcceptJSON(r.Header) {
+		http.Error(w, "JSON only acceptable response", http.StatusNotAcceptable)
+		return
+	}
 	indexName := mux.Vars(r)["index"]
 	for _, idx := range h.API.Schema(r.Context()) {
 		if idx.Name == indexName {
@@ -429,6 +466,10 @@ type postIndexResponse struct{}
 
 // handleDeleteIndex handles DELETE /index request.
 func (h *Handler) handleDeleteIndex(w http.ResponseWriter, r *http.Request) {
+	if checkHeaderAcceptJSON(r.Header) {
+		http.Error(w, "JSON only acceptable response", http.StatusNotAcceptable)
+		return
+	}
 	indexName := mux.Vars(r)["index"]
 	err := h.API.DeleteIndex(r.Context(), indexName)
 	if err != nil {
@@ -447,6 +488,10 @@ type deleteIndexResponse struct{}
 
 // handlePostIndex handles POST /index request.
 func (h *Handler) handlePostIndex(w http.ResponseWriter, r *http.Request) {
+	if checkHeaderAcceptJSON(r.Header) {
+		http.Error(w, "JSON only acceptable response", http.StatusNotAcceptable)
+		return
+	}
 	indexName := mux.Vars(r)["index"]
 
 	// Decode request.
@@ -477,6 +522,10 @@ func (h *Handler) handlePostIndex(w http.ResponseWriter, r *http.Request) {
 
 // handlePostIndexAttrDiff handles POST /index/attr/diff requests.
 func (h *Handler) handlePostIndexAttrDiff(w http.ResponseWriter, r *http.Request) {
+	if checkHeaderAcceptJSON(r.Header) {
+		http.Error(w, "JSON only acceptable response", http.StatusNotAcceptable)
+		return
+	}
 	indexName := mux.Vars(r)["index"]
 
 	// Decode request.
@@ -514,6 +563,10 @@ type postIndexAttrDiffResponse struct {
 
 // handlePostField handles POST /field request.
 func (h *Handler) handlePostField(w http.ResponseWriter, r *http.Request) {
+	if checkHeaderAcceptJSON(r.Header) {
+		http.Error(w, "JSON only acceptable response", http.StatusNotAcceptable)
+		return
+	}
 	indexName := mux.Vars(r)["index"]
 	fieldName := mux.Vars(r)["field"]
 
@@ -592,6 +645,11 @@ type postFieldResponse struct{}
 
 // handleDeleteField handles DELETE /field request.
 func (h *Handler) handleDeleteField(w http.ResponseWriter, r *http.Request) {
+	if checkHeaderAcceptJSON(r.Header) {
+		http.Error(w, "JSON only acceptable response", http.StatusNotAcceptable)
+		return
+	}
+
 	indexName := mux.Vars(r)["index"]
 	fieldName := mux.Vars(r)["field"]
 
@@ -617,6 +675,10 @@ type deleteFieldResponse struct{}
 
 // handlePostFieldAttrDiff handles POST /field/attr/diff requests.
 func (h *Handler) handlePostFieldAttrDiff(w http.ResponseWriter, r *http.Request) {
+	if checkHeaderAcceptJSON(r.Header) {
+		http.Error(w, "JSON only acceptable response", http.StatusNotAcceptable)
+		return
+	}
 	indexName := mux.Vars(r)["index"]
 	fieldName := mux.Vars(r)["field"]
 
@@ -709,7 +771,7 @@ func (h *Handler) readURLQueryRequest(r *http.Request) (*pilosa.QueryRequest, er
 
 // writeQueryResponse writes the response from the executor to w.
 func (h *Handler) writeQueryResponse(w http.ResponseWriter, r *http.Request, resp *pilosa.QueryResponse) error {
-	if strings.Contains(r.Header.Get("Accept"), "application/x-protobuf") {
+	if checkHeaderAcceptJSON(r.Header) {
 		return h.writeProtobufQueryResponse(w, resp)
 	}
 	return h.writeJSONQueryResponse(w, resp)
@@ -872,6 +934,10 @@ func (h *Handler) handleGetExportCSV(w http.ResponseWriter, r *http.Request) {
 
 // handleGetFragmentNodes handles /fragment/nodes requests.
 func (h *Handler) handleGetFragmentNodes(w http.ResponseWriter, r *http.Request) {
+	if checkHeaderAcceptJSON(r.Header) {
+		http.Error(w, "JSON only acceptable response", http.StatusNotAcceptable)
+		return
+	}
 	q := r.URL.Query()
 	index := q.Get("index")
 
@@ -917,6 +983,10 @@ func (h *Handler) handleGetFragmentBlockData(w http.ResponseWriter, r *http.Requ
 
 // handleGetFragmentBlocks handles GET /fragment/blocks requests.
 func (h *Handler) handleGetFragmentBlocks(w http.ResponseWriter, r *http.Request) {
+	if checkHeaderAcceptJSON(r.Header) {
+		http.Error(w, "JSON only acceptable response", http.StatusNotAcceptable)
+		return
+	}
 	// Read slice parameter.
 	q := r.URL.Query()
 	slice, err := strconv.ParseUint(q.Get("slice"), 10, 64)
@@ -949,6 +1019,10 @@ type getFragmentBlocksResponse struct {
 
 // handleGetVersion handles /version requests.
 func (h *Handler) handleGetVersion(w http.ResponseWriter, r *http.Request) {
+	if checkHeaderAcceptJSON(r.Header) {
+		http.Error(w, "JSON only acceptable response", http.StatusNotAcceptable)
+		return
+	}
 	err := json.NewEncoder(w).Encode(struct {
 		Version string `json:"version"`
 	}{
@@ -1047,6 +1121,10 @@ func errorString(err error) string {
 }
 
 func (h *Handler) handlePostClusterResizeSetCoordinator(w http.ResponseWriter, r *http.Request) {
+	if checkHeaderAcceptJSON(r.Header) {
+		http.Error(w, "JSON only acceptable response", http.StatusNotAcceptable)
+		return
+	}
 	// Decode request.
 	var req setCoordinatorRequest
 	err := json.NewDecoder(r.Body).Decode(&req)
@@ -1084,6 +1162,10 @@ type setCoordinatorResponse struct {
 
 // handlePostClusterResizeRemoveNode handles POST /cluster/resize/remove-node request.
 func (h *Handler) handlePostClusterResizeRemoveNode(w http.ResponseWriter, r *http.Request) {
+	if checkHeaderAcceptJSON(r.Header) {
+		http.Error(w, "JSON only acceptable response", http.StatusNotAcceptable)
+		return
+	}
 	// Decode request.
 	var req removeNodeRequest
 	err := json.NewDecoder(r.Body).Decode(&req)
@@ -1120,6 +1202,10 @@ type removeNodeResponse struct {
 
 // handlePostClusterResizeAbort handles POST /cluster/resize/abort request.
 func (h *Handler) handlePostClusterResizeAbort(w http.ResponseWriter, r *http.Request) {
+	if checkHeaderAcceptJSON(r.Header) {
+		http.Error(w, "JSON only acceptable response", http.StatusNotAcceptable)
+		return
+	}
 	err := h.API.ResizeAbort()
 	var msg string
 	if err != nil {
@@ -1157,6 +1243,10 @@ func (h *Handler) handleRecalculateCaches(w http.ResponseWriter, r *http.Request
 }
 
 func (h *Handler) handlePostClusterMessage(w http.ResponseWriter, r *http.Request) {
+	if checkHeaderAcceptJSON(r.Header) {
+		http.Error(w, "JSON only acceptable response", http.StatusNotAcceptable)
+		return
+	}
 	// Verify that request is only communicating over protobufs.
 	if r.Header.Get("Content-Type") != "application/x-protobuf" {
 		http.Error(w, "Unsupported media type", http.StatusUnsupportedMediaType)
diff --git a/http/handler_test.go b/http/handler_test.go
index 2f3ab0aba..ddedef49a 100644
--- a/http/handler_test.go
+++ b/http/handler_test.go
@@ -750,11 +750,17 @@ func TestHandler_Index_AttrStore_Diff(t *testing.T) {
 	blks[1].Checksum = []byte("MISMATCHED_CHECKSUM")
 
 	// Send block checksums to determine diff.
-	resp, err := gohttp.Post(
+	req, err := gohttp.NewRequest(
+		"POST",
 		s.URL+"/index/i/attr/diff",
-		"application/json",
 		strings.NewReader(`{"blocks":`+string(test.MustMarshalJSON(blks))+`}`),
 	)
+
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Accept", "application/json")
+
+	client := &gohttp.Client{}
+	resp, err := client.Do(req)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -800,11 +806,17 @@ func TestHandler_Field_AttrStore_Diff(t *testing.T) {
 	blks[1].Checksum = []byte("MISMATCHED_CHECKSUM")
 
 	// Send block checksums to determine diff.
-	resp, err := gohttp.Post(
+	req, err := gohttp.NewRequest(
+		"POST",
 		s.URL+"/index/i/field/meta/attr/diff",
-		"application/json",
 		strings.NewReader(`{"blocks":`+string(test.MustMarshalJSON(blks))+`}`),
 	)
+
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Accept", "application/json")
+
+	client := &gohttp.Client{}
+	resp, err := client.Do(req)
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/test/handler.go b/test/handler.go
index 27fa20503..5256413b5 100644
--- a/test/handler.go
+++ b/test/handler.go
@@ -148,6 +148,7 @@ func MustParseURLHost(rawurl string) string {
 // MustNewHTTPRequest creates a new HTTP request. Panic on error.
 func MustNewHTTPRequest(method, urlStr string, body io.Reader) *gohttp.Request {
 	req, err := gohttp.NewRequest(method, urlStr, body)
+	req.Header.Add("Accept", "application/json")
 	if err != nil {
 		panic(err)
 	}
diff --git a/test/pilosa.go b/test/pilosa.go
index bd1628aa6..757e5a96c 100644
--- a/test/pilosa.go
+++ b/test/pilosa.go
@@ -263,10 +263,15 @@ func (m *Main) RecalculateCaches() error {
 
 // MustDo executes http.Do() with an http.NewRequest(). Panic on error.
 func MustDo(method, urlStr string, body string) *httpResponse {
-	req, err := gohttp.NewRequest(method, urlStr, strings.NewReader(body))
-	if err != nil {
-		panic(err)
-	}
+	req, err := gohttp.NewRequest(
+		method,
+		urlStr,
+		strings.NewReader(body),
+	)
+
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Accept", "application/json")
+
 	resp, err := gohttp.DefaultClient.Do(req)
 	if err != nil {
 		panic(err)
diff --git a/test/pilosa_test.go b/test/pilosa_test.go
index 583a244c0..0a1acc551 100644
--- a/test/pilosa_test.go
+++ b/test/pilosa_test.go
@@ -17,6 +17,7 @@ package test_test
 import (
 	"encoding/json"
 	"net/http"
+	"strings"
 	"testing"
 
 	"github.com/pilosa/pilosa"
@@ -32,12 +33,21 @@ func TestNewCluster(t *testing.T) {
 			t.Fatalf("node %d does not have the same coordinator as node 0. '%v' and '%v' respectively", i, coordi, coordinator)
 		}
 	}
+	req, err := http.NewRequest(
+		"GET",
+		"http://"+cluster[0].Server.Addr().String()+"/status",
+		strings.NewReader(""),
+	)
 
-	response, err := http.Get("http://" + cluster[0].Server.Addr().String() + "/status")
+	req.Header.Set("Accept", "application/json")
+
+	resp, err := http.DefaultClient.Do(req)
 	if err != nil {
-		t.Fatalf("getting schema: %v", err)
+		t.Fatalf("sending request: %v", err)
 	}
-	dec := json.NewDecoder(response.Body)
+	defer resp.Body.Close()
+
+	dec := json.NewDecoder(resp.Body)
 	body := struct {
 		State string
 		Nodes []struct {