diff --git a/app/vmagent/prometheusimport/request_handler.go b/app/vmagent/prometheusimport/request_handler.go
index 571860e25..84ede2e1b 100644
--- a/app/vmagent/prometheusimport/request_handler.go
+++ b/app/vmagent/prometheusimport/request_handler.go
@@ -1,12 +1,13 @@
 package prometheusimport
 
 import (
-	"io"
 	"net/http"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/app/vmagent/common"
 	"github.com/VictoriaMetrics/VictoriaMetrics/app/vmagent/remotewrite"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/auth"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/httpserver"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/prompbmarshal"
 	parserCommon "github.com/VictoriaMetrics/VictoriaMetrics/lib/protoparser/common"
 	parser "github.com/VictoriaMetrics/VictoriaMetrics/lib/protoparser/prometheus"
@@ -30,17 +31,14 @@ func InsertHandler(at *auth.Token, req *http.Request) error {
 	if err != nil {
 		return err
 	}
+	remoteAddr := httpserver.GetQuotedRemoteAddr(req)
+	uri := httpserver.GetRequestURI(req)
 	isGzipped := req.Header.Get("Content-Encoding") == "gzip"
 	return parser.ParseStream(req.Body, defaultTimestamp, isGzipped, func(rows []parser.Row) error {
 		return insertRows(at, rows, extraLabels)
-	}, nil)
-}
-
-// InsertHandlerForReader processes metrics from given reader with optional gzip format
-func InsertHandlerForReader(r io.Reader, isGzipped bool) error {
-	return parser.ParseStream(r, 0, isGzipped, func(rows []parser.Row) error {
-		return insertRows(nil, rows, nil)
-	}, nil)
+	}, func(s string) {
+		logger.Errorf("error parsing prometheus text protocol, uri - %s, remote address - %q: %s", uri, remoteAddr, s)
+	})
 }
 
 func insertRows(at *auth.Token, rows []parser.Row, extraLabels []prompbmarshal.Label) error {
diff --git a/app/vmagent/prometheusimport/request_handler_test.go b/app/vmagent/prometheusimport/request_handler_test.go
new file mode 100644
index 000000000..6883da2b6
--- /dev/null
+++ b/app/vmagent/prometheusimport/request_handler_test.go
@@ -0,0 +1,55 @@
+package prometheusimport
+
+import (
+	"bytes"
+	"flag"
+	"log"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/VictoriaMetrics/VictoriaMetrics/app/vmagent/remotewrite"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/protoparser/common"
+)
+
+var (
+	srv        *httptest.Server
+	testOutput *bytes.Buffer
+)
+
+func TestInsertHandler(t *testing.T) {
+	setUp()
+	defer tearDown()
+	req := httptest.NewRequest("POST", "/insert/0/api/v1/import/prometheus", bytes.NewBufferString(`{"foo":"bar"}
+go_memstats_alloc_bytes_total 1`))
+	if err := InsertHandler(nil, req); err != nil {
+		t.Errorf("unxepected error %s", err)
+	}
+	if msg := "error parsing prometheus text protocol"; !strings.Contains(testOutput.String(), msg) {
+		t.Errorf("output %q should contain %q", testOutput.String(), msg)
+	}
+}
+
+func setUp() {
+	srv = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.WriteHeader(204)
+	}))
+	flag.Parse()
+	remoteWriteFlag := "remoteWrite.url"
+	if err := flag.Lookup(remoteWriteFlag).Value.Set(srv.URL); err != nil {
+		log.Fatalf("unable to set %q with value %q, err: %v", remoteWriteFlag, srv.URL, err)
+	}
+	logger.Init()
+	common.StartUnmarshalWorkers()
+	remotewrite.Init()
+	testOutput = &bytes.Buffer{}
+	logger.SetOutputForTests(testOutput)
+}
+
+func tearDown() {
+	common.StopUnmarshalWorkers()
+	srv.Close()
+	logger.ResetOutputForTest()
+}
diff --git a/app/vminsert/prometheusimport/request_handler.go b/app/vminsert/prometheusimport/request_handler.go
index 0afccf45b..12b1fe90e 100644
--- a/app/vminsert/prometheusimport/request_handler.go
+++ b/app/vminsert/prometheusimport/request_handler.go
@@ -5,6 +5,8 @@ import (
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/app/vminsert/common"
 	"github.com/VictoriaMetrics/VictoriaMetrics/app/vminsert/relabel"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/httpserver"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/prompbmarshal"
 	parserCommon "github.com/VictoriaMetrics/VictoriaMetrics/lib/protoparser/common"
 	parser "github.com/VictoriaMetrics/VictoriaMetrics/lib/protoparser/prometheus"
@@ -26,10 +28,14 @@ func InsertHandler(req *http.Request) error {
 	if err != nil {
 		return err
 	}
+	remoteAddr := httpserver.GetQuotedRemoteAddr(req)
+	uri := httpserver.GetRequestURI(req)
 	isGzipped := req.Header.Get("Content-Encoding") == "gzip"
 	return parser.ParseStream(req.Body, defaultTimestamp, isGzipped, func(rows []parser.Row) error {
 		return insertRows(rows, extraLabels)
-	}, nil)
+	}, func(s string) {
+		logger.Errorf("error parsing prometheus text protocol, uri - %s, remote address - %q: %s", uri, remoteAddr, s)
+	})
 }
 
 func insertRows(rows []parser.Row, extraLabels []prompbmarshal.Label) error {
diff --git a/lib/logger/logger.go b/lib/logger/logger.go
index 97539b29e..3b973a81c 100644
--- a/lib/logger/logger.go
+++ b/lib/logger/logger.go
@@ -315,3 +315,9 @@ func shouldSkipLog(level string) bool {
 		return false
 	}
 }
+
+// SetOutputForTests redefine output for logger. Use for Tests only. Call ResetOutputForTest to return output state to default
+func SetOutputForTests(writer io.Writer) { output = writer }
+
+// ResetOutputForTest set logger output to default value
+func ResetOutputForTest() { output = os.Stderr }
diff --git a/lib/protoparser/prometheus/streamparser.go b/lib/protoparser/prometheus/streamparser.go
index b7e8a2bff..0a0b55477 100644
--- a/lib/protoparser/prometheus/streamparser.go
+++ b/lib/protoparser/prometheus/streamparser.go
@@ -179,7 +179,7 @@ func (uw *unmarshalWork) Unmarshal() {
 	// Fill missing timestamps with the current timestamp.
 	defaultTimestamp := uw.defaultTimestamp
 	if defaultTimestamp <= 0 {
-		defaultTimestamp = int64(time.Now().UnixNano() / 1e6)
+		defaultTimestamp = time.Now().UnixNano() / 1e6
 	}
 	for i := range rows {
 		r := &rows[i]