diff --git a/src/go/Makefile b/src/go/Makefile
index f3162e52..06732e63 100644
--- a/src/go/Makefile
+++ b/src/go/Makefile
@@ -1,13 +1,14 @@
-GO    := GO15VENDOREXPERIMENT=1 go
+GO := go
 pkgs   = $(shell $(GO) list ./... | grep -v /vendor/)
 VERSION=$(git describe --tags)                                                   
 BUILD=$(date +%FT%T%z)
 
 PREFIX=$(shell pwd)
-BIN_DIR=$(shell pwd)
+BIN_DIR=$(shell git rev-parse --show-toplevel)/bin
+LDFLAGS="-w -s -X main.Version=${VERSION} -X main.Build=${BUILD}"
 
 
-all: format build test
+all: format gox test
 
 style:
 	@echo ">> checking code style"
@@ -25,8 +26,24 @@ vet:
 	@echo ">> vetting code"
 	@$(GO) vet $(pkgs)
 
-build: 
-	@echo ">> building binaries"
-	@$(GO) build -ldflags "-w -s -X main.Version=${VERSION} -X main.Build=${BUILD}"
+build-all: 
+	@echo ">> building all binaries in $(BIN_DIR). OS & platform will be appended to the file name"
+	@gox build -ldflags $(LDFLAGS) -osarch="linux/amd64 linux/386 darwin/amd64 darwin/386" -output=$(BIN_DIR)"/{{.Dir}}_{{.OS}}_{{.Arch}}" $(pkgs)
+
+linux-amd64: 
+	@echo ">> building linux/amd64 binaries in $(BIN_DIR)"
+	gox -ldflags $(LDFLAGS) -osarch="linux/amd64" -output=$(BIN_DIR)"/{{.Dir}}" $(pkgs)
+
+linux-386: 
+	@echo ">> building linux/386 binaries in $(BIN_DIR)"
+	gox -ldflags $(LDFLAGS) -osarch="linux/amd64" -output=$(BIN_DIR)"/{{.Dir}}" $(pkgs)
+
+darwin-amd64: 
+	@echo ">> building darwin/amd64 binaries in $(BIN_DIR)"
+	gox -ldflags $(LDFLAGS) -osarch="darwin/amd64" -output=$(BIN_DIR)"/{{.Dir}}" $(pkgs)
+
+darwin-386: 
+	@echo ">> building darwin/386 binaries in $(BIN_DIR)"
+	gox -ldflags $(LDFLAGS) -osarch="darwin/386" -output=$(BIN_DIR)"/{{.Dir}}" $(pkgs)
 
 .PHONY: all style format build test vet tarball 
diff --git a/src/go/mongolib/proto/server_status.go b/src/go/mongolib/proto/server_status.go
index 44b1a0f6..2585f77b 100644
--- a/src/go/mongolib/proto/server_status.go
+++ b/src/go/mongolib/proto/server_status.go
@@ -159,12 +159,12 @@ type NetworkStats struct {
 
 // OpcountStats stores information related to comamnds and basic CRUD operations.
 type OpcountStats struct {
+	Command int64 `bson:"command"`
+	Delete  int64 `bson:"delete"`
+	GetMore int64 `bson:"getmore"`
 	Insert  int64 `bson:"insert"`
 	Query   int64 `bson:"query"`
 	Update  int64 `bson:"update"`
-	Delete  int64 `bson:"delete"`
-	GetMore int64 `bson:"getmore"`
-	Command int64 `bson:"command"`
 }
 
 // ReadWriteLockTimes stores time spent holding read/write locks.
diff --git a/src/go/pt-mongodb-summary/main.go b/src/go/pt-mongodb-summary/main.go
index 591711b0..8b21e805 100644
--- a/src/go/pt-mongodb-summary/main.go
+++ b/src/go/pt-mongodb-summary/main.go
@@ -476,20 +476,51 @@ func getNodeType(session pmgo.SessionManager) (string, error) {
 
 func GetOpCountersStats(session pmgo.SessionManager, count int64, sleep time.Duration) (*opCounters, error) {
 	oc := &opCounters{}
+	previousoc := &opCounters{}
 	ss := proto.ServerStatus{}
 
-	err := session.DB("admin").Run(bson.D{{"serverStatus", 1}, {"recordStats", 1}}, &ss)
-	if err != nil {
-		return nil, errors.Wrap(err, "GetOpCountersStats.ServerStatus")
-	}
-
 	ticker := time.NewTicker(sleep)
-	for i := int64(0); i < count-1; i++ {
+	for i := int64(0); i < count; i++ {
 		<-ticker.C
 		err := session.DB("admin").Run(bson.D{{"serverStatus", 1}, {"recordStats", 1}}, &ss)
 		if err != nil {
+			panic(err)
+		}
+
+		if i == 0 {
+			previousoc.Command.Total = ss.Opcounters.Command
+			previousoc.Delete.Total = ss.Opcounters.Delete
+			previousoc.GetMore.Total = ss.Opcounters.GetMore
+			previousoc.Insert.Total = ss.Opcounters.Insert
+			previousoc.Query.Total = ss.Opcounters.Query
+			previousoc.Update.Total = ss.Opcounters.Update
 			continue
 		}
+
+		ss.Opcounters.Command -= previousoc.Command.Total
+		ss.Opcounters.Delete -= previousoc.Delete.Total
+		ss.Opcounters.GetMore -= previousoc.GetMore.Total
+		ss.Opcounters.Insert -= previousoc.Insert.Total
+		ss.Opcounters.Query -= previousoc.Query.Total
+		ss.Opcounters.Update -= previousoc.Update.Total
+
+		// Be careful. This cannot be item[0] because we need value - prev_value
+		// and at pos 0 there is no prev value
+		if i == 1 {
+			oc.Command.Max = ss.Opcounters.Command
+			oc.Command.Min = ss.Opcounters.Command
+			oc.Delete.Max = ss.Opcounters.Delete
+			oc.Delete.Min = ss.Opcounters.Delete
+			oc.GetMore.Max = ss.Opcounters.GetMore
+			oc.GetMore.Min = ss.Opcounters.GetMore
+			oc.Insert.Max = ss.Opcounters.Insert
+			oc.Insert.Min = ss.Opcounters.Insert
+			oc.Query.Max = ss.Opcounters.Query
+			oc.Query.Min = ss.Opcounters.Query
+			oc.Update.Max = ss.Opcounters.Update
+			oc.Update.Min = ss.Opcounters.Update
+		}
+
 		// Insert
 		if ss.Opcounters.Insert > oc.Insert.Max {
 			oc.Insert.Max = ss.Opcounters.Insert
@@ -543,6 +574,14 @@ func GetOpCountersStats(session pmgo.SessionManager, count int64, sleep time.Dur
 			oc.GetMore.Min = ss.Opcounters.GetMore
 		}
 		oc.GetMore.Total += ss.Opcounters.GetMore
+
+		previousoc.Insert.Total = ss.Opcounters.Insert
+		previousoc.Query.Total = ss.Opcounters.Query
+		previousoc.Command.Total = ss.Opcounters.Command
+		previousoc.Update.Total = ss.Opcounters.Update
+		previousoc.Delete.Total = ss.Opcounters.Delete
+		previousoc.GetMore.Total = ss.Opcounters.GetMore
+
 	}
 	ticker.Stop()
 
diff --git a/src/go/pt-mongodb-summary/main_test.go b/src/go/pt-mongodb-summary/main_test.go
index 4b21870f..edf17f94 100644
--- a/src/go/pt-mongodb-summary/main_test.go
+++ b/src/go/pt-mongodb-summary/main_test.go
@@ -25,21 +25,25 @@ func TestGetOpCounterStats(t *testing.T) {
 	ss := proto.ServerStatus{}
 	test.LoadJson("test/sample/serverstatus.json", &ss)
 
-	// serverStatus for getOpCountersStats
 	session.EXPECT().DB("admin").Return(database)
 	database.EXPECT().Run(bson.D{{"serverStatus", 1}, {"recordStats", 1}}, gomock.Any()).SetArg(1, ss)
+
 	session.EXPECT().DB("admin").Return(database)
 	database.EXPECT().Run(bson.D{{"serverStatus", 1}, {"recordStats", 1}}, gomock.Any()).SetArg(1, ss)
+
 	session.EXPECT().DB("admin").Return(database)
 	database.EXPECT().Run(bson.D{{"serverStatus", 1}, {"recordStats", 1}}, gomock.Any()).SetArg(1, ss)
+
 	session.EXPECT().DB("admin").Return(database)
 	database.EXPECT().Run(bson.D{{"serverStatus", 1}, {"recordStats", 1}}, gomock.Any()).SetArg(1, ss)
+
+	ss = addToCounters(ss, 1)
 	session.EXPECT().DB("admin").Return(database)
 	database.EXPECT().Run(bson.D{{"serverStatus", 1}, {"recordStats", 1}}, gomock.Any()).SetArg(1, ss)
 
 	var sampleCount int64 = 5
 	var sampleRate time.Duration = 10 * time.Millisecond // in seconds
-	expect := timedStats{Min: 0, Max: 473, Total: 1892, Avg: 378}
+	expect := timedStats{Min: 7, Max: 7, Total: 7, Avg: 1}
 
 	os, err := GetOpCountersStats(session, sampleCount, sampleRate)
 	if err != nil {
@@ -51,6 +55,16 @@ func TestGetOpCounterStats(t *testing.T) {
 
 }
 
+func addToCounters(ss proto.ServerStatus, increment int64) proto.ServerStatus {
+	ss.Opcounters.Command += increment
+	ss.Opcounters.Delete += increment
+	ss.Opcounters.GetMore += increment
+	ss.Opcounters.Insert += increment
+	ss.Opcounters.Query += increment
+	ss.Opcounters.Update += increment
+	return ss
+}
+
 func TestSecurityOpts(t *testing.T) {
 	cmdopts := []proto.CommandLineOptions{
 		// 1
diff --git a/src/go/pt-mongodb-summary/test/sample/serverstatus.json b/src/go/pt-mongodb-summary/test/sample/serverstatus.json
index 624185d3..f366a133 100644
--- a/src/go/pt-mongodb-summary/test/sample/serverstatus.json
+++ b/src/go/pt-mongodb-summary/test/sample/serverstatus.json
@@ -34,12 +34,12 @@
         "NumRequests": 522
     },
     "Opcounters": {
-        "Insert": 0,
-        "Query": 22,
-        "Update": 0,
-        "Delete": 0,
-        "GetMore": 0,
-        "Command": 473
+        "Insert": 1,
+        "Query": 2,
+        "Update": 3,
+        "Delete": 4,
+        "GetMore": 5,
+        "Command": 6
     },
     "OpcountersRepl": null,
     "RecordStats": null,
@@ -55,4 +55,4 @@
     "ShardCursorType": null,
     "StorageEngine": null,
     "WiredTiger": null
-}
\ No newline at end of file
+}