diff --git a/builtin/providers/aws/resource_aws_codebuild_project.go b/builtin/providers/aws/resource_aws_codebuild_project.go
index 0f9bb9be7..9643dffe6 100644
--- a/builtin/providers/aws/resource_aws_codebuild_project.go
+++ b/builtin/providers/aws/resource_aws_codebuild_project.go
@@ -503,12 +503,17 @@ func flattenAwsCodebuildProjectSource(source *codebuild.ProjectSource) *schema.S
 		F: resourceAwsCodeBuildProjectSourceHash,
 	}
 
+	authSet := schema.Set{
+		F: resourceAwsCodeBuildProjectSourceAuthHash,
+	}
+
 	sourceConfig := map[string]interface{}{}
 
 	sourceConfig["type"] = *source.Type
 
 	if source.Auth != nil {
-		sourceConfig["auth"] = sourceAuthToMap(source.Auth)
+		authSet.Add(sourceAuthToMap(source.Auth))
+		sourceConfig["auth"] = &authSet
 	}
 
 	if source.Buildspec != nil {
@@ -566,6 +571,19 @@ func resourceAwsCodeBuildProjectSourceHash(v interface{}) int {
 	return hashcode.String(buf.String())
 }
 
+func resourceAwsCodeBuildProjectSourceAuthHash(v interface{}) int {
+	var buf bytes.Buffer
+	m := v.(map[string]interface{})
+
+	authType := m["type"].(string)
+	authResource := m["resource"].(string)
+
+	buf.WriteString(fmt.Sprintf("%s-", authType))
+	buf.WriteString(fmt.Sprintf("%s-", authResource))
+
+	return hashcode.String(buf.String())
+}
+
 func environmentVariablesToMap(environmentVariables []*codebuild.EnvironmentVariable) []map[string]interface{} {
 
 	envVariables := make([]map[string]interface{}, len(environmentVariables))
diff --git a/builtin/providers/aws/resource_aws_codebuild_project_test.go b/builtin/providers/aws/resource_aws_codebuild_project_test.go
index a21fe0f2a..949a6fb29 100644
--- a/builtin/providers/aws/resource_aws_codebuild_project_test.go
+++ b/builtin/providers/aws/resource_aws_codebuild_project_test.go
@@ -355,6 +355,10 @@ resource "aws_codebuild_project" "foo" {
   }
 
   source {
+    auth {
+      type = "OAUTH"
+    }
+
     type     = "GITHUB"
     location = "https://github.com/mitchellh/packer.git"
   }