diff --git a/lib/protoparser/csvimport/streamparser.go b/lib/protoparser/csvimport/streamparser.go
index cd0bd0314a..247526b8bd 100644
--- a/lib/protoparser/csvimport/streamparser.go
+++ b/lib/protoparser/csvimport/streamparser.go
@@ -48,7 +48,7 @@ func ParseStream(req *http.Request, callback func(rows []Row) error) error {
 		uw := getUnmarshalWork()
 		uw.callback = callback
 		uw.cds = cds
-		uw.reqBuf = append(uw.reqBuf[:0], ctx.reqBuf...)
+		uw.reqBuf, ctx.reqBuf = ctx.reqBuf, uw.reqBuf
 		common.ScheduleUnmarshalWork(uw)
 	}
 	return ctx.Error()
diff --git a/lib/protoparser/graphite/streamparser.go b/lib/protoparser/graphite/streamparser.go
index f553d529ac..2eea19bd5a 100644
--- a/lib/protoparser/graphite/streamparser.go
+++ b/lib/protoparser/graphite/streamparser.go
@@ -33,7 +33,7 @@ func ParseStream(r io.Reader, callback func(rows []Row) error) error {
 	for ctx.Read() {
 		uw := getUnmarshalWork()
 		uw.callback = callback
-		uw.reqBuf = append(uw.reqBuf[:0], ctx.reqBuf...)
+		uw.reqBuf, ctx.reqBuf = ctx.reqBuf, uw.reqBuf
 		common.ScheduleUnmarshalWork(uw)
 	}
 	return ctx.Error()
diff --git a/lib/protoparser/influx/streamparser.go b/lib/protoparser/influx/streamparser.go
index bf4d6f5522..5b0fd3287f 100644
--- a/lib/protoparser/influx/streamparser.go
+++ b/lib/protoparser/influx/streamparser.go
@@ -59,7 +59,7 @@ func ParseStream(r io.Reader, isGzipped bool, precision, db string, callback fun
 		uw.callback = callback
 		uw.db = db
 		uw.tsMultiplier = tsMultiplier
-		uw.reqBuf = append(uw.reqBuf[:0], ctx.reqBuf...)
+		uw.reqBuf, ctx.reqBuf = ctx.reqBuf, uw.reqBuf
 		common.ScheduleUnmarshalWork(uw)
 	}
 	return ctx.Error()
diff --git a/lib/protoparser/opentsdb/streamparser.go b/lib/protoparser/opentsdb/streamparser.go
index bc9507f74f..cf2b4f89eb 100644
--- a/lib/protoparser/opentsdb/streamparser.go
+++ b/lib/protoparser/opentsdb/streamparser.go
@@ -32,7 +32,7 @@ func ParseStream(r io.Reader, callback func(rows []Row) error) error {
 	for ctx.Read() {
 		uw := getUnmarshalWork()
 		uw.callback = callback
-		uw.reqBuf = append(uw.reqBuf[:0], ctx.reqBuf...)
+		uw.reqBuf, ctx.reqBuf = ctx.reqBuf, uw.reqBuf
 		common.ScheduleUnmarshalWork(uw)
 	}
 	return ctx.Error()
diff --git a/lib/protoparser/opentsdbhttp/streamparser.go b/lib/protoparser/opentsdbhttp/streamparser.go
index bc8d9ca770..9a7ffaa5f3 100644
--- a/lib/protoparser/opentsdbhttp/streamparser.go
+++ b/lib/protoparser/opentsdbhttp/streamparser.go
@@ -59,7 +59,7 @@ func ParseStream(req *http.Request, callback func(rows []Row) error) error {
 
 	uw := getUnmarshalWork()
 	uw.callback = callback
-	uw.reqBuf = append(uw.reqBuf[:0], ctx.reqBuf.B...)
+	uw.reqBuf, ctx.reqBuf.B = ctx.reqBuf.B, uw.reqBuf
 	common.ScheduleUnmarshalWork(uw)
 	return nil
 }
diff --git a/lib/protoparser/prometheus/streamparser.go b/lib/protoparser/prometheus/streamparser.go
index 061a7dc360..cfee948cbd 100644
--- a/lib/protoparser/prometheus/streamparser.go
+++ b/lib/protoparser/prometheus/streamparser.go
@@ -34,7 +34,7 @@ func ParseStream(r io.Reader, defaultTimestamp int64, isGzipped bool, callback f
 		uw := getUnmarshalWork()
 		uw.callback = callback
 		uw.defaultTimestamp = defaultTimestamp
-		uw.reqBuf = append(uw.reqBuf[:0], ctx.reqBuf...)
+		uw.reqBuf, ctx.reqBuf = ctx.reqBuf, uw.reqBuf
 		common.ScheduleUnmarshalWork(uw)
 	}
 	return ctx.Error()
diff --git a/lib/protoparser/promremotewrite/streamparser.go b/lib/protoparser/promremotewrite/streamparser.go
index a6c88b58a7..4312310d62 100644
--- a/lib/protoparser/promremotewrite/streamparser.go
+++ b/lib/protoparser/promremotewrite/streamparser.go
@@ -30,7 +30,7 @@ func ParseStream(req *http.Request, callback func(tss []prompb.TimeSeries) error
 	}
 	uw := getUnmarshalWork()
 	uw.callback = callback
-	uw.reqBuf = append(uw.reqBuf[:0], ctx.reqBuf.B...)
+	uw.reqBuf, ctx.reqBuf.B = ctx.reqBuf.B, uw.reqBuf
 	common.ScheduleUnmarshalWork(uw)
 	return nil
 }
diff --git a/lib/protoparser/vmimport/streamparser.go b/lib/protoparser/vmimport/streamparser.go
index f0eefdfe46..915ac18e8e 100644
--- a/lib/protoparser/vmimport/streamparser.go
+++ b/lib/protoparser/vmimport/streamparser.go
@@ -39,7 +39,7 @@ func ParseStream(req *http.Request, callback func(rows []Row) error) error {
 	for ctx.Read() {
 		uw := getUnmarshalWork()
 		uw.callback = callback
-		uw.reqBuf = append(uw.reqBuf[:0], ctx.reqBuf...)
+		uw.reqBuf, ctx.reqBuf = ctx.reqBuf, uw.reqBuf
 		common.ScheduleUnmarshalWork(uw)
 	}
 	return ctx.Error()