diff --git a/action/get.go b/action/get.go
index 5665ef6..58384de 100644
--- a/action/get.go
+++ b/action/get.go
@@ -5,6 +5,7 @@
 	"path/filepath"
 	"strings"
 
+	"github.com/Masterminds/glide/cache"
 	"github.com/Masterminds/glide/cfg"
 	"github.com/Masterminds/glide/godep"
 	"github.com/Masterminds/glide/msg"
@@ -17,6 +18,10 @@
 //
 // This includes resolving dependency resolution and re-generating the lock file.
 func Get(names []string, installer *repo.Installer, insecure, skipRecursive, strip, stripVendor bool) {
+	if installer.UseCache {
+		cache.SystemLock()
+	}
+
 	base := gpath.Basepath()
 	EnsureGopath()
 	EnsureVendorDir()
diff --git a/action/install.go b/action/install.go
index 3ae39c0..25a5f08 100644
--- a/action/install.go
+++ b/action/install.go
@@ -4,6 +4,7 @@
 	"io/ioutil"
 	"path/filepath"
 
+	"github.com/Masterminds/glide/cache"
 	"github.com/Masterminds/glide/cfg"
 	"github.com/Masterminds/glide/dependency"
 	"github.com/Masterminds/glide/msg"
@@ -13,6 +14,10 @@
 
 // Install installs a vendor directory based on an existing Glide configuration.
 func Install(installer *repo.Installer, strip, stripVendor bool) {
+	if installer.UseCache {
+		cache.SystemLock()
+	}
+
 	base := "."
 	// Ensure GOPATH
 	EnsureGopath()
diff --git a/action/update.go b/action/update.go
index 4b0da7b..eb49baa 100644
--- a/action/update.go
+++ b/action/update.go
@@ -3,6 +3,7 @@
 import (
 	"path/filepath"
 
+	"github.com/Masterminds/glide/cache"
 	"github.com/Masterminds/glide/cfg"
 	"github.com/Masterminds/glide/dependency"
 	"github.com/Masterminds/glide/godep"
@@ -13,6 +14,10 @@
 
 // Update updates repos and the lock file from the main glide yaml.
 func Update(installer *repo.Installer, skipRecursive, strip, stripVendor bool) {
+	if installer.UseCache {
+		cache.SystemLock()
+	}
+
 	base := "."
 	EnsureGopath()
 	EnsureVendorDir()
diff --git a/cache/global_lock.go b/cache/global_lock.go
new file mode 100644
index 0000000..f823a6d
--- /dev/null
+++ b/cache/global_lock.go
@@ -0,0 +1,109 @@
+package cache
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/Masterminds/glide/msg"
+	gpath "github.com/Masterminds/glide/path"
+)
+
+var isStarted bool
+
+// SystemLock starts a system rather than application lock. This way multiple
+// app instances don't cause race conditions when working in the cache.
+func SystemLock() error {
+	if isStarted {
+		return nil
+	}
+	err := waitOnLock()
+	if err != nil {
+		return err
+	}
+	err = startLock()
+	isStarted = true
+	return err
+}
+
+// SystemUnlock removes the system wide Glide cache lock.
+func SystemUnlock() {
+	lockdone <- struct{}{}
+	os.Remove(lockFileName)
+}
+
+var lockdone = make(chan struct{}, 1)
+
+type lockdata struct {
+	Comment string `json:"comment"`
+	Pid     int    `json:"pid"`
+	Time    string `json:"time"`
+}
+
+var lockFileName = filepath.Join(gpath.Home(), "lock.json")
+
+// Write a lock for now.
+func writeLock() error {
+	ld := &lockdata{
+		Comment: "File managed by Glide (https://glide.sh)",
+		Pid:     os.Getpid(),
+		Time:    time.Now().Format(time.RFC3339Nano),
+	}
+
+	out, err := json.Marshal(ld)
+	if err != nil {
+		return err
+	}
+	err = ioutil.WriteFile(lockFileName, out, 0755)
+	return err
+}
+
+func startLock() error {
+	err := writeLock()
+	if err != nil {
+		return err
+	}
+
+	go func() {
+		select {
+		case <-lockdone:
+			return
+		default:
+			//time.Sleep(10 * time.Second)
+			err := writeLock()
+			if err != nil {
+				msg.Die("Error using Glide lock: %s", err)
+			}
+		}
+	}()
+
+	return nil
+}
+
+func waitOnLock() error {
+	var announced bool
+	for {
+		fi, err := os.Stat(lockFileName)
+		if err != nil && os.IsNotExist(err) {
+			return nil
+		} else if err != nil {
+			return err
+		}
+
+		diff := time.Now().Sub(fi.ModTime())
+		if diff.Seconds() > 15 {
+			return nil
+		}
+
+		if !announced {
+			announced = true
+			msg.Info("Waiting on global cache access")
+		}
+
+		// Check on the lock file every 15 seconds.
+		// TODO(mattfarina): should this be a different length?
+		time.Sleep(15 * time.Second)
+	}
+}
diff --git a/glide.go b/glide.go
index a9f43ea..2ce9fcc 100644
--- a/glide.go
+++ b/glide.go
@@ -40,6 +40,7 @@
 	"path/filepath"
 
 	"github.com/Masterminds/glide/action"
+	"github.com/Masterminds/glide/cache"
 	"github.com/Masterminds/glide/msg"
 	gpath "github.com/Masterminds/glide/path"
 	"github.com/Masterminds/glide/repo"
@@ -110,6 +111,7 @@
 		action.Plugin(command, os.Args)
 	}
 	app.Before = startup
+	app.After = shutdown
 	app.Commands = commands()
 
 	// Detect errors from the Before and After calls and exit on them.
@@ -669,6 +671,11 @@
 	return nil
 }
 
+func shutdown(c *cli.Context) error {
+	cache.SystemUnlock()
+	return nil
+}
+
 // Get the path to the glide.yaml file.
 //
 // This returns the name of the path, even if the file does not exist. The value