diff --git a/terraform/eval_interpolate.go b/terraform/eval_interpolate.go
index df3bcb98e..78c881360 100644
--- a/terraform/eval_interpolate.go
+++ b/terraform/eval_interpolate.go
@@ -9,14 +9,19 @@ import (
 // EvalInterpolate is an EvalNode implementation that takes a raw
 // configuration and interpolates it.
 type EvalInterpolate struct {
-	Config   *config.RawConfig
-	Resource *Resource
-	Output   **ResourceConfig
+	Config        *config.RawConfig
+	Resource      *Resource
+	Output        **ResourceConfig
+	ContinueOnErr bool
 }
 
 func (n *EvalInterpolate) Eval(ctx EvalContext) (interface{}, error) {
 	rc, err := ctx.Interpolate(n.Config, n.Resource)
 	if err != nil {
+		if n.ContinueOnErr {
+			log.Printf("[WARN] Interpolation %q failed: %s", n.Config.Key, err)
+			return nil, EvalEarlyExitError{}
+		}
 		return nil, err
 	}
 
@@ -26,28 +31,3 @@ func (n *EvalInterpolate) Eval(ctx EvalContext) (interface{}, error) {
 
 	return nil, nil
 }
-
-// EvalTryInterpolate is an EvalNode implementation that takes a raw
-// configuration and interpolates it, but only logs a warning on an
-// interpolation error, and stops further Eval steps.
-// This is used during Input where a value may not be known before Refresh, but
-// we don't want to block Input.
-type EvalTryInterpolate struct {
-	Config   *config.RawConfig
-	Resource *Resource
-	Output   **ResourceConfig
-}
-
-func (n *EvalTryInterpolate) Eval(ctx EvalContext) (interface{}, error) {
-	rc, err := ctx.Interpolate(n.Config, n.Resource)
-	if err != nil {
-		log.Printf("[WARN] Interpolation %q failed: %s", n.Config.Key, err)
-		return nil, EvalEarlyExitError{}
-	}
-
-	if n.Output != nil {
-		*n.Output = rc
-	}
-
-	return nil, nil
-}
diff --git a/terraform/graph_builder_input.go b/terraform/graph_builder_input.go
index 10fd8b1e9..0df48cdb8 100644
--- a/terraform/graph_builder_input.go
+++ b/terraform/graph_builder_input.go
@@ -10,9 +10,6 @@ import (
 // and is based on the PlanGraphBuilder. The PlanGraphBuilder passed in will be
 // modified and should not be used for any other operations.
 func InputGraphBuilder(p *PlanGraphBuilder) GraphBuilder {
-	// convert this to an InputPlan
-	p.Input = true
-
 	// We're going to customize the concrete functions
 	p.CustomConcrete = true
 
diff --git a/terraform/graph_builder_plan.go b/terraform/graph_builder_plan.go
index 9d05d4a43..429e42481 100644
--- a/terraform/graph_builder_plan.go
+++ b/terraform/graph_builder_plan.go
@@ -40,9 +40,6 @@ type PlanGraphBuilder struct {
 	// Validate will do structural validation of the graph.
 	Validate bool
 
-	// Input represents that this builder is for an Input operation.
-	Input bool
-
 	// CustomConcrete can be set to customize the node types created
 	// for various parts of the plan. This is useful in order to customize
 	// the plan behavior.
@@ -115,7 +112,6 @@ func (b *PlanGraphBuilder) Steps() []GraphTransformer {
 		// Add module variables
 		&ModuleVariableTransformer{
 			Module: b.Module,
-			Input:  b.Input,
 		},
 
 		// Connect so that the references are ready for targeting. We'll
diff --git a/terraform/node_module_variable.go b/terraform/node_module_variable.go
index 63b84a9c5..66ff7d5e3 100644
--- a/terraform/node_module_variable.go
+++ b/terraform/node_module_variable.go
@@ -15,9 +15,6 @@ type NodeApplyableModuleVariable struct {
 	Value     *config.RawConfig // Value is the value that is set
 
 	Module *module.Tree // Antiquated, want to remove
-
-	// Input is set if this graph was created for the Input operation.
-	Input bool
 }
 
 func (n *NodeApplyableModuleVariable) Name() string {
@@ -96,23 +93,24 @@ func (n *NodeApplyableModuleVariable) EvalTree() EvalNode {
 	var config *ResourceConfig
 	variables := make(map[string]interface{})
 
-	var interpolate EvalNode
-
-	if n.Input {
-		interpolate = &EvalTryInterpolate{
-			Config: n.Value,
-			Output: &config,
-		}
-	} else {
-		interpolate = &EvalInterpolate{
-			Config: n.Value,
-			Output: &config,
-		}
-	}
-
 	return &EvalSequence{
 		Nodes: []EvalNode{
-			interpolate,
+			&EvalOpFilter{
+				Ops: []walkOperation{walkInput},
+				Node: &EvalInterpolate{
+					Config:        n.Value,
+					Output:        &config,
+					ContinueOnErr: true,
+				},
+			},
+			&EvalOpFilter{
+				Ops: []walkOperation{walkRefresh, walkPlan, walkApply,
+					walkDestroy, walkValidate},
+				Node: &EvalInterpolate{
+					Config: n.Value,
+					Output: &config,
+				},
+			},
 
 			&EvalVariableBlock{
 				Config:         &config,
diff --git a/terraform/transform_module_variable.go b/terraform/transform_module_variable.go
index dbfd16871..467950bdc 100644
--- a/terraform/transform_module_variable.go
+++ b/terraform/transform_module_variable.go
@@ -17,7 +17,6 @@ type ModuleVariableTransformer struct {
 	Module *module.Tree
 
 	DisablePrune bool // True if pruning unreferenced should be disabled
-	Input        bool // True if this is from an Input operation.
 }
 
 func (t *ModuleVariableTransformer) Transform(g *Graph) error {
@@ -100,7 +99,6 @@ func (t *ModuleVariableTransformer) transformSingle(g *Graph, parent, m *module.
 			Config:    v,
 			Value:     value,
 			Module:    t.Module,
-			Input:     t.Input,
 		}
 
 		if !t.DisablePrune {