diff --git a/google/iam_project.go b/google/iam_project.go
index 192dab4a..476a458c 100644
--- a/google/iam_project.go
+++ b/google/iam_project.go
@@ -2,6 +2,7 @@ package google
 
 import (
 	"fmt"
+
 	"github.com/hashicorp/errwrap"
 	"github.com/hashicorp/terraform/helper/schema"
 	"google.golang.org/api/cloudresourcemanager/v1"
@@ -65,7 +66,7 @@ func (u *ProjectIamUpdater) GetResourceId() string {
 }
 
 func (u *ProjectIamUpdater) GetMutexKey() string {
-	return fmt.Sprintf("iam-project-%s", u.resourceId)
+	return getProjectIamPolicyMutexKey(u.resourceId)
 }
 
 func (u *ProjectIamUpdater) DescribeResource() string {
diff --git a/google/resource_google_project_iam_policy.go b/google/resource_google_project_iam_policy.go
index 306037e8..1107cc53 100644
--- a/google/resource_google_project_iam_policy.go
+++ b/google/resource_google_project_iam_policy.go
@@ -61,6 +61,11 @@ func resourceGoogleProjectIamPolicyCreate(d *schema.ResourceData, meta interface
 	if err != nil {
 		return err
 	}
+
+	mutexKey := getProjectIamPolicyMutexKey(pid)
+	mutexKV.Lock(mutexKey)
+	defer mutexKV.Unlock(mutexKey)
+
 	// Get the policy in the template
 	p, err := getResourceIamPolicy(d)
 	if err != nil {
@@ -153,6 +158,10 @@ func resourceGoogleProjectIamPolicyUpdate(d *schema.ResourceData, meta interface
 		return err
 	}
 
+	mutexKey := getProjectIamPolicyMutexKey(pid)
+	mutexKV.Lock(mutexKey)
+	defer mutexKV.Unlock(mutexKey)
+
 	// Get the policy in the template
 	p, err := getResourceIamPolicy(d)
 	if err != nil {
@@ -220,6 +229,10 @@ func resourceGoogleProjectIamPolicyDelete(d *schema.ResourceData, meta interface
 		return err
 	}
 
+	mutexKey := getProjectIamPolicyMutexKey(pid)
+	mutexKV.Lock(mutexKey)
+	defer mutexKV.Unlock(mutexKey)
+
 	// Get the existing IAM policy from the API
 	ep, err := getProjectIamPolicy(pid, config)
 	if err != nil {
@@ -400,3 +413,7 @@ func (b sortableBindings) Swap(i, j int) {
 func (b sortableBindings) Less(i, j int) bool {
 	return b[i].Role < b[j].Role
 }
+
+func getProjectIamPolicyMutexKey(pid string) string {
+	return fmt.Sprintf("iam-project-%s", pid)
+}