diff --git a/config/config.go b/config/config.go
index 2083c7fc7..656f33a62 100644
--- a/config/config.go
+++ b/config/config.go
@@ -131,6 +131,9 @@ func (c *Config) Validate() error {
 		varMap[v.Name] = v
 	}
 
+	// TODO(mitchellh): Validate that variable defaults are only a string
+	// or mapping of strings.
+
 	// Check for references to user variables that do not actually
 	// exist and record those errors.
 	for source, vs := range vars {
diff --git a/config/config_test.go b/config/config_test.go
index 4c66466b1..f4a2ce0d7 100644
--- a/config/config_test.go
+++ b/config/config_test.go
@@ -64,6 +64,24 @@ func TestConfigValidate_unknownVar(t *testing.T) {
 	}
 }
 
+func TestConfigValidate_varDefault(t *testing.T) {
+	c := testConfig(t, "validate-var-default")
+	if err := c.Validate(); err != nil {
+		t.Fatalf("should be valid: %s", err)
+	}
+}
+
+func TestConfigValidate_varDefaultBadType(t *testing.T) {
+	t.Skip()
+
+	// TODO(mitchellh): FIX
+
+	c := testConfig(t, "validate-var-default-bad-type")
+	if err := c.Validate(); err == nil {
+		t.Fatal("should not be valid")
+	}
+}
+
 func TestNewResourceVariable(t *testing.T) {
 	v, err := NewResourceVariable("foo.bar.baz")
 	if err != nil {
diff --git a/config/loader_libucl.go b/config/loader_libucl.go
index 398c2f5fd..176c588bd 100644
--- a/config/loader_libucl.go
+++ b/config/loader_libucl.go
@@ -51,11 +51,13 @@ func (t *libuclConfigurable) Config() (*Config, error) {
 	if len(rawConfig.Variable) > 0 {
 		config.Variables = make([]*Variable, 0, len(rawConfig.Variable))
 		for k, v := range rawConfig.Variable {
-			config.Variables = append(config.Variables, &Variable{
+			newVar := &Variable{
 				Name:        k,
 				Default:     v.Default,
 				Description: v.Description,
-			})
+			}
+
+			config.Variables = append(config.Variables, newVar)
 		}
 	}
 
diff --git a/config/test-fixtures/validate-var-default-bad-type/main.tf b/config/test-fixtures/validate-var-default-bad-type/main.tf
new file mode 100644
index 000000000..c7975db38
--- /dev/null
+++ b/config/test-fixtures/validate-var-default-bad-type/main.tf
@@ -0,0 +1,3 @@
+variable "foo" {
+  default = ["foo", "bar"]
+}
diff --git a/config/test-fixtures/validate-var-default/main.tf b/config/test-fixtures/validate-var-default/main.tf
new file mode 100644
index 000000000..75a6bc9e0
--- /dev/null
+++ b/config/test-fixtures/validate-var-default/main.tf
@@ -0,0 +1,9 @@
+variable "foo" {
+  default = "bar"
+}
+
+variable "foo" {
+  default = {
+    "foo" = "bar"
+  }
+}