diff --git a/helper/multierror/error.go b/helper/multierror/error.go
index cddd2fc84..5bfe2b14d 100644
--- a/helper/multierror/error.go
+++ b/helper/multierror/error.go
@@ -23,6 +23,10 @@ func (e *Error) Error() string {
 		len(e.Errors), strings.Join(points, "\n"))
 }
 
+func (e *Error) GoString() string {
+	return fmt.Sprintf("*%#v", *e)
+}
+
 // ErrorAppend is a helper function that will append more errors
 // onto a Error in order to create a larger multi-error. If the
 // original error is not a Error, it will be turned into one.
diff --git a/terraform/context_test.go b/terraform/context_test.go
index ec49e5a90..1cf797c7e 100644
--- a/terraform/context_test.go
+++ b/terraform/context_test.go
@@ -1050,6 +1050,14 @@ func TestContextApply_vars(t *testing.T) {
 		},
 	})
 
+	w, e := ctx.Validate()
+	if len(w) > 0 {
+		t.Fatalf("bad: %#v", w)
+	}
+	if len(e) > 0 {
+		t.Fatalf("bad: %s", e)
+	}
+
 	if _, err := ctx.Plan(nil); err != nil {
 		t.Fatalf("err: %s", err)
 	}
diff --git a/terraform/semantics_test.go b/terraform/semantics_test.go
index 9d7d30ebc..018f448b1 100644
--- a/terraform/semantics_test.go
+++ b/terraform/semantics_test.go
@@ -18,4 +18,13 @@ func TestSMCUserVariables(t *testing.T) {
 	if len(errs) != 0 {
 		t.Fatalf("err: %#v", errs)
 	}
+
+	// Mapping element override
+	errs = smcUserVariables(c, map[string]string{
+		"foo":     "bar",
+		"map.foo": "baz",
+	})
+	if len(errs) != 0 {
+		t.Fatalf("err: %#v", errs)
+	}
 }
diff --git a/terraform/test-fixtures/apply-vars/main.tf b/terraform/test-fixtures/apply-vars/main.tf
index e250d0f98..6645e532d 100644
--- a/terraform/test-fixtures/apply-vars/main.tf
+++ b/terraform/test-fixtures/apply-vars/main.tf
@@ -9,6 +9,8 @@ variable "bar" {
     default = "baz"
 }
 
+variable "foo" {}
+
 resource "aws_instance" "foo" {
     num = "2"
     bar = "${var.bar}"
diff --git a/terraform/test-fixtures/smc-uservars/main.tf b/terraform/test-fixtures/smc-uservars/main.tf
index 7e2d10c11..cfa329378 100644
--- a/terraform/test-fixtures/smc-uservars/main.tf
+++ b/terraform/test-fixtures/smc-uservars/main.tf
@@ -6,3 +6,10 @@ variable "foo" {
 variable "bar" {
     default = "baz"
 }
+
+# Mapping
+variable "map" {
+    default = {
+        "foo" = "bar";
+    }
+}