diff --git a/CHANGELOG.md b/CHANGELOG.md
index 33861d704..24ffa7855 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,7 @@ BUG FIXES:
   * core: If a resource fails to create and has provisioners, it is
       marked as tainted. [GH-434]
   * core: Set types are validated to be sets. [GH-413]
+  * core: String types are validated properly. [GH-460]
   * core: Fix crash case when destroying with tainted resources. [GH-412]
   * core: Don't execute provisioners in some cases on destroy.
   * core: Inherited provider configurations will be properly interpolated. [GH-418]
diff --git a/helper/schema/schema.go b/helper/schema/schema.go
index 6b0afa6b2..c0fb99210 100644
--- a/helper/schema/schema.go
+++ b/helper/schema/schema.go
@@ -823,12 +823,26 @@ func (m schemaMap) validatePrimitive(
 		fallthrough
 	case TypeList:
 		return m.validateList(k, raw, schema, c)
+	case TypeBool:
+		// Verify that we can parse this as the correct type
+		var n bool
+		if err := mapstructure.WeakDecode(raw, &n); err != nil {
+			return nil, []error{err}
+		}
 	case TypeInt:
 		// Verify that we can parse this as an int
 		var n int
 		if err := mapstructure.WeakDecode(raw, &n); err != nil {
 			return nil, []error{err}
 		}
+	case TypeString:
+		// Verify that we can parse this as a string
+		var n string
+		if err := mapstructure.WeakDecode(raw, &n); err != nil {
+			return nil, []error{err}
+		}
+	default:
+		panic(fmt.Sprintf("Unknown validation type: %s", schema.Type))
 	}
 
 	return nil, nil
diff --git a/helper/schema/schema_test.go b/helper/schema/schema_test.go
index ea71351ef..e966eb34b 100644
--- a/helper/schema/schema_test.go
+++ b/helper/schema/schema_test.go
@@ -1788,6 +1788,25 @@ func TestSchemaMap_Validate(t *testing.T) {
 			Err: true,
 		},
 
+		{
+			Schema: map[string]*Schema{
+				"user_data": &Schema{
+					Type:     TypeString,
+					Optional: true,
+				},
+			},
+
+			Config: map[string]interface{}{
+				"user_data": []interface{}{
+					map[string]interface{}{
+						"foo": "bar",
+					},
+				},
+			},
+
+			Err: true,
+		},
+
 		// Bad type, interpolated
 		{
 			Schema: map[string]*Schema{