diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2b19e0d51..bb0dfc47e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,8 @@ BUG FIXES:
   * core: Remove panic case when applying with a plan that generates no
       new state. [GH-403]
   * core: Fix a hang that can occur with enough resources. [GH-410]
+  * core: Config validation will not error if the field is being
+      computed so the value is still unknown.
 
 ## 0.3.0 (October 14, 2014)
 
diff --git a/helper/schema/schema.go b/helper/schema/schema.go
index 7e26741ff..d074e9512 100644
--- a/helper/schema/schema.go
+++ b/helper/schema/schema.go
@@ -813,6 +813,11 @@ func (m schemaMap) validatePrimitive(
 	raw interface{},
 	schema *Schema,
 	c *terraform.ResourceConfig) ([]string, []error) {
+	if c.IsComputed(k) {
+		// If the key is being computed, then it is not an error
+		return nil, nil
+	}
+
 	switch schema.Type {
 	case TypeList:
 		return m.validateList(k, raw, schema, c)
diff --git a/helper/schema/schema_test.go b/helper/schema/schema_test.go
index d25ce32d0..66830869c 100644
--- a/helper/schema/schema_test.go
+++ b/helper/schema/schema_test.go
@@ -1720,6 +1720,7 @@ func TestSchemaMap_Validate(t *testing.T) {
 	cases := []struct {
 		Schema map[string]*Schema
 		Config map[string]interface{}
+		Vars   map[string]string
 		Warn   bool
 		Err    bool
 	}{
@@ -1739,6 +1740,24 @@ func TestSchemaMap_Validate(t *testing.T) {
 			},
 		},
 
+		// Good, because the var is not set and that error will come elsewhere
+		{
+			Schema: map[string]*Schema{
+				"size": &Schema{
+					Type:     TypeInt,
+					Required: true,
+				},
+			},
+
+			Config: map[string]interface{}{
+				"size": "${var.foo}",
+			},
+
+			Vars: map[string]string{
+				"var.foo": config.UnknownVariableValue,
+			},
+		},
+
 		// Required field not set
 		{
 			Schema: map[string]*Schema{
@@ -1769,6 +1788,26 @@ func TestSchemaMap_Validate(t *testing.T) {
 			Err: true,
 		},
 
+		// Bad type, interpolated
+		{
+			Schema: map[string]*Schema{
+				"size": &Schema{
+					Type:     TypeInt,
+					Required: true,
+				},
+			},
+
+			Config: map[string]interface{}{
+				"size": "${var.foo}",
+			},
+
+			Vars: map[string]string{
+				"var.foo": "nope",
+			},
+
+			Err: true,
+		},
+
 		// Required but has DefaultFunc
 		{
 			Schema: map[string]*Schema{
@@ -1938,6 +1977,11 @@ func TestSchemaMap_Validate(t *testing.T) {
 		if err != nil {
 			t.Fatalf("err: %s", err)
 		}
+		if tc.Vars != nil {
+			if err := c.Interpolate(tc.Vars); err != nil {
+				t.Fatalf("err: %s", err)
+			}
+		}
 
 		ws, es := schemaMap(tc.Schema).Validate(terraform.NewResourceConfig(c))
 		if (len(es) > 0) != tc.Err {