diff --git a/builder/dockerfile/dispatchers.go b/builder/dockerfile/dispatchers.go
index 715161270d..f83a17ce33 100644
--- a/builder/dockerfile/dispatchers.go
+++ b/builder/dockerfile/dispatchers.go
@@ -315,10 +315,6 @@ func workdir(req dispatchRequest) error {
 		return nil
 	}
 
-	// TODO: why is this done here. This seems to be done at random places all over
-	// the builder
-	req.runConfig.Image = req.builder.image
-
 	comment := "WORKDIR " + req.runConfig.WorkingDir
 	runConfigWithCommentCmd := copyRunConfig(req.runConfig, withCmdCommentString(comment))
 	if hit, err := req.builder.probeCache(req.builder.image, runConfigWithCommentCmd); err != nil || hit {
@@ -372,9 +368,6 @@ func run(req dispatchRequest) error {
 		saveCmd = prependEnvOnCmd(req.builder.buildArgs, buildArgs, cmdFromArgs)
 	}
 
-	// TODO: this was previously in b.create(), why is it necessary?
-	req.runConfig.Image = req.builder.image
-
 	runConfigForCacheProbe := copyRunConfig(req.runConfig, withCmd(saveCmd))
 	hit, err := req.builder.probeCache(req.builder.image, runConfigForCacheProbe)
 	if err != nil || hit {
diff --git a/builder/dockerfile/evaluator.go b/builder/dockerfile/evaluator.go
index abad15e096..e98a4e2f0d 100644
--- a/builder/dockerfile/evaluator.go
+++ b/builder/dockerfile/evaluator.go
@@ -173,7 +173,14 @@ func (b *Builder) dispatch(stepN int, stepTotal int, node *parser.Node, shlex *S
 	// XXX yes, we skip any cmds that are not valid; the parser should have
 	// picked these out already.
 	if f, ok := evaluateTable[cmd]; ok {
-		return f(newDispatchRequestFromNode(node, b, strList, shlex))
+		if err := f(newDispatchRequestFromNode(node, b, strList, shlex)); err != nil {
+			return err
+		}
+		// TODO: return an object instead of setting things on builder
+		// If the step created a new image set it as the imageID for the
+		// current runConfig
+		b.runConfig.Image = b.image
+		return nil
 	}
 
 	return fmt.Errorf("Unknown instruction: %s", upperCasedCmd)
diff --git a/builder/dockerfile/internals.go b/builder/dockerfile/internals.go
index a772c615a8..ec411c4638 100644
--- a/builder/dockerfile/internals.go
+++ b/builder/dockerfile/internals.go
@@ -42,8 +42,6 @@ func (b *Builder) commit(comment string) error {
 	if !b.hasFromImage() {
 		return errors.New("Please provide a source image with `from` prior to commit")
 	}
-	// TODO: why is this set here?
-	b.runConfig.Image = b.image
 
 	runConfigWithCommentCmd := copyRunConfig(b.runConfig, withCmdComment(comment))
 	hit, err := b.probeCache(b.image, runConfigWithCommentCmd)
@@ -100,10 +98,6 @@ func (b *Builder) runContextCommand(args []string, allowRemote bool, allowLocalD
 	// Work in daemon-specific filepath semantics
 	dest := filepath.FromSlash(args[len(args)-1]) // last one is always the dest
 
-	// TODO: why is this done here. This seems to be done at random places all over
-	// the builder
-	b.runConfig.Image = b.image
-
 	var infos []copyInfo
 
 	// Loop through each src file and calculate the info we need to
@@ -542,12 +536,12 @@ func (b *Builder) processImageFrom(img builder.Image) error {
 // If an image is found, probeCache returns `(true, nil)`.
 // If no image is found, it returns `(false, nil)`.
 // If there is any error, it returns `(false, err)`.
-func (b *Builder) probeCache(imageID string, runConfig *container.Config) (bool, error) {
+func (b *Builder) probeCache(parentID string, runConfig *container.Config) (bool, error) {
 	c := b.imageCache
 	if c == nil || b.options.NoCache || b.cacheBusted {
 		return false, nil
 	}
-	cache, err := c.GetCache(imageID, runConfig)
+	cache, err := c.GetCache(parentID, runConfig)
 	if err != nil {
 		return false, err
 	}