diff --git a/Makefile b/Makefile
index 148cb5758..4bcdab299 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@
 # with Go source code. If you know what GOPATH is then you probably
 # don't need to bother with make.
 
-.PHONY: geth geth-cross evm all test xgo clean
+.PHONY: geth geth-cross evm all test clean
 .PHONY: geth-linux geth-linux-386 geth-linux-amd64
 .PHONY: geth-linux-arm geth-linux-arm-5 geth-linux-arm-6 geth-linux-arm-7 geth-linux-arm64
 .PHONY: geth-darwin geth-darwin-386 geth-darwin-amd64
@@ -33,9 +33,6 @@ clean:
 
 # Cross Compilation Targets (xgo)
 
-xgo:
-	build/env.sh go get github.com/karalabe/xgo
-
 geth-cross: geth-linux geth-darwin geth-windows geth-android geth-ios
 	@echo "Full cross compilation done:"
 	@ls -ld $(GOBIN)/geth-*
@@ -44,13 +41,13 @@ geth-linux: geth-linux-386 geth-linux-amd64 geth-linux-arm
 	@echo "Linux cross compilation done:"
 	@ls -ld $(GOBIN)/geth-linux-*
 
-geth-linux-386: xgo
-	build/env.sh $(GOBIN)/xgo --go=$(GO) --dest=$(GOBIN) --targets=linux/386 -v $(shell build/flags.sh) ./cmd/geth
+geth-linux-386:
+	build/env.sh go run build/ci.go xgo --go=$(GO) --dest=$(GOBIN) --targets=linux/386 -v ./cmd/geth
 	@echo "Linux 386 cross compilation done:"
 	@ls -ld $(GOBIN)/geth-linux-* | grep 386
 
-geth-linux-amd64: xgo
-	build/env.sh $(GOBIN)/xgo --go=$(GO) --dest=$(GOBIN) --targets=linux/amd64 -v $(shell build/flags.sh) ./cmd/geth
+geth-linux-amd64:
+	build/env.sh go run build/ci.go xgo --go=$(GO) --dest=$(GOBIN) --targets=linux/amd64 -v ./cmd/geth
 	@echo "Linux amd64 cross compilation done:"
 	@ls -ld $(GOBIN)/geth-linux-* | grep amd64
 
@@ -58,23 +55,23 @@ geth-linux-arm: geth-linux-arm-5 geth-linux-arm-6 geth-linux-arm-7 geth-linux-ar
 	@echo "Linux ARM cross compilation done:"
 	@ls -ld $(GOBIN)/geth-linux-* | grep arm
 
-geth-linux-arm-5: xgo
-	build/env.sh $(GOBIN)/xgo --go=$(GO) --dest=$(GOBIN) --targets=linux/arm-5 -v $(shell build/flags.sh) ./cmd/geth
+geth-linux-arm-5:
+	build/env.sh go run build/ci.go xgo --go=$(GO) --dest=$(GOBIN) --targets=linux/arm-5 -v ./cmd/geth
 	@echo "Linux ARMv5 cross compilation done:"
 	@ls -ld $(GOBIN)/geth-linux-* | grep arm-5
 
-geth-linux-arm-6: xgo
-	build/env.sh $(GOBIN)/xgo --go=$(GO) --dest=$(GOBIN) --targets=linux/arm-6 -v $(shell build/flags.sh) ./cmd/geth
+geth-linux-arm-6:
+	build/env.sh go run build/ci.go xgo --go=$(GO) --dest=$(GOBIN) --targets=linux/arm-6 -v ./cmd/geth
 	@echo "Linux ARMv6 cross compilation done:"
 	@ls -ld $(GOBIN)/geth-linux-* | grep arm-6
 
-geth-linux-arm-7: xgo
-	build/env.sh $(GOBIN)/xgo --go=$(GO) --dest=$(GOBIN) --targets=linux/arm-7 -v $(shell build/flags.sh) ./cmd/geth
+geth-linux-arm-7:
+	build/env.sh go run build/ci.go xgo --go=$(GO) --dest=$(GOBIN) --targets=linux/arm-7 -v ./cmd/geth
 	@echo "Linux ARMv7 cross compilation done:"
 	@ls -ld $(GOBIN)/geth-linux-* | grep arm-7
 
-geth-linux-arm64: xgo
-	build/env.sh $(GOBIN)/xgo --go=$(GO) --dest=$(GOBIN) --targets=linux/arm64 -v $(shell build/flags.sh) ./cmd/geth
+geth-linux-arm64:
+	build/env.sh go run build/ci.go xgo --go=$(GO) --dest=$(GOBIN) --targets=linux/arm64 -v ./cmd/geth
 	@echo "Linux ARM64 cross compilation done:"
 	@ls -ld $(GOBIN)/geth-linux-* | grep arm64
 
@@ -82,13 +79,13 @@ geth-darwin: geth-darwin-386 geth-darwin-amd64
 	@echo "Darwin cross compilation done:"
 	@ls -ld $(GOBIN)/geth-darwin-*
 
-geth-darwin-386: xgo
-	build/env.sh $(GOBIN)/xgo --go=$(GO) --dest=$(GOBIN) --targets=darwin/386 -v $(shell build/flags.sh) ./cmd/geth
+geth-darwin-386:
+	build/env.sh go run build/ci.go xgo --go=$(GO) --dest=$(GOBIN) --targets=darwin/386 -v ./cmd/geth
 	@echo "Darwin 386 cross compilation done:"
 	@ls -ld $(GOBIN)/geth-darwin-* | grep 386
 
-geth-darwin-amd64: xgo
-	build/env.sh $(GOBIN)/xgo --go=$(GO) --dest=$(GOBIN) --targets=darwin/amd64 -v $(shell build/flags.sh) ./cmd/geth
+geth-darwin-amd64:
+	build/env.sh go run build/ci.go xgo --go=$(GO) --dest=$(GOBIN) --targets=darwin/amd64 -v ./cmd/geth
 	@echo "Darwin amd64 cross compilation done:"
 	@ls -ld $(GOBIN)/geth-darwin-* | grep amd64
 
@@ -96,22 +93,22 @@ geth-windows: geth-windows-386 geth-windows-amd64
 	@echo "Windows cross compilation done:"
 	@ls -ld $(GOBIN)/geth-windows-*
 
-geth-windows-386: xgo
-	build/env.sh $(GOBIN)/xgo --go=$(GO) --dest=$(GOBIN) --targets=windows/386 -v $(shell build/flags.sh) ./cmd/geth
+geth-windows-386:
+	build/env.sh go run build/ci.go xgo --go=$(GO) --dest=$(GOBIN) --targets=windows/386 -v ./cmd/geth
 	@echo "Windows 386 cross compilation done:"
 	@ls -ld $(GOBIN)/geth-windows-* | grep 386
 
-geth-windows-amd64: xgo
-	build/env.sh $(GOBIN)/xgo --go=$(GO) --dest=$(GOBIN) --targets=windows/amd64 -v $(shell build/flags.sh) ./cmd/geth
+geth-windows-amd64:
+	build/env.sh go run build/ci.go xgo --go=$(GO) --dest=$(GOBIN) --targets=windows/amd64 -v ./cmd/geth
 	@echo "Windows amd64 cross compilation done:"
 	@ls -ld $(GOBIN)/geth-windows-* | grep amd64
 
-geth-android: xgo
-	build/env.sh $(GOBIN)/xgo --go=$(GO) --dest=$(GOBIN) --targets=android-21/aar -v $(shell build/flags.sh) ./cmd/geth
+geth-android:
+	build/env.sh go run build/ci.go xgo --go=$(GO) --dest=$(GOBIN) --targets=android-21/aar -v ./cmd/geth
 	@echo "Android cross compilation done:"
 	@ls -ld $(GOBIN)/geth-android-*
 
-geth-ios: xgo
-	build/env.sh $(GOBIN)/xgo --go=$(GO) --dest=$(GOBIN) --targets=ios-7.0/framework -v $(shell build/flags.sh) ./cmd/geth
+geth-ios:
+	build/env.sh go run build/ci.go xgo --go=$(GO) --dest=$(GOBIN) --targets=ios-7.0/framework -v ./cmd/geth
 	@echo "iOS framework cross compilation done:"
 	@ls -ld $(GOBIN)/geth-ios-*
diff --git a/build/ci.go b/build/ci.go
index 33d97c182..3011a6976 100644
--- a/build/ci.go
+++ b/build/ci.go
@@ -28,6 +28,7 @@ Available commands are:
    archive    [ -type zip|tar ]                        -- archives build artefacts
    importkeys                                          -- imports signing keys from env
    debsrc     [ -sign key-id ] [ -upload dest ]        -- creates a debian source package
+   xgo        [ options ]                              -- cross builds according to options
 
 For all commands, -n prevents execution of external programs (dry run mode).
 
@@ -121,6 +122,8 @@ func main() {
 		doDebianSource(os.Args[2:])
 	case "travis-debsrc":
 		doTravisDebianSource(os.Args[2:])
+	case "xgo":
+		doXgo(os.Args[2:])
 	default:
 		log.Fatal("unknown command ", os.Args[1])
 	}
@@ -463,3 +466,32 @@ func stageDebianSource(tmpdir string, meta debMetadata) (pkgdir string) {
 
 	return pkgdir
 }
+
+// Cross compilation
+
+func doXgo(cmdline []string) {
+	// Make sure xgo is available for cross compilation
+	gogetxgo := goTool("get", "github.com/karalabe/xgo")
+	build.MustRun(gogetxgo)
+
+	// Execute the actual cross compilation
+	pkg := cmdline[len(cmdline)-1]
+	args := append(cmdline[:len(cmdline)-1], makeBuildFlags("")...)
+
+	build.MustRun(xgoTool(append(args, pkg)...))
+}
+
+func xgoTool(args ...string) *exec.Cmd {
+	cmd := exec.Command(filepath.Join(GOBIN, "xgo"), args...)
+	cmd.Env = []string{
+		"GOPATH=" + build.GOPATH(),
+		"GOBIN=" + GOBIN,
+	}
+	for _, e := range os.Environ() {
+		if strings.HasPrefix(e, "GOPATH=") || strings.HasPrefix(e, "GOBIN=") {
+			continue
+		}
+		cmd.Env = append(cmd.Env, e)
+	}
+	return cmd
+}
diff --git a/build/flags.sh b/build/flags.sh
deleted file mode 100755
index e021dbad4..000000000
--- a/build/flags.sh
+++ /dev/null
@@ -1,22 +0,0 @@
-#!/bin/sh
-
-set -e
-
-if [ ! -f "build/env.sh" ]; then
-    echo "$0 must be run from the root of the repository."
-    exit 2
-fi
-
-# Since Go 1.5, the separator char for link time assignments
-# is '=' and using ' ' prints a warning. However, Go < 1.5 does
-# not support using '='.
-sep=$(go version | awk '{ if ($3 >= "go1.5" || index($3, "devel")) print "="; else print " "; }' -)
-
-# set gitCommit when running from a Git checkout.
-if [ -f ".git/HEAD" ]; then
-    echo "-ldflags '-X main.gitCommit$sep$(git rev-parse HEAD)'"
-fi
-
-if [ ! -z "$GO_OPENCL" ]; then
-   echo "-tags opencl"
-fi