diff --git a/docker/applyupdate.go b/docker/applyupdate.go
index 36ece95..9de682c 100644
--- a/docker/applyupdate.go
+++ b/docker/applyupdate.go
@@ -34,7 +34,7 @@ func (u *Updater) ApplyUpdate(ctx context.Context, update updater.Update) error
 		var oldnew []string
 		var seenFrom bool
 		for _, instruction := range parsed.AST.Children {
-			switch instruction.Value {
+			switch strings.ToLower(instruction.Value) {
 			case command.From:
 				seenFrom = true
 				dep := parseDependency(vars, instruction.Next.Value)
diff --git a/docker/dependencies.go b/docker/dependencies.go
index d6a900a..35ba705 100644
--- a/docker/dependencies.go
+++ b/docker/dependencies.go
@@ -34,7 +34,7 @@ func extractImages(parsed *parser.Result) ([]updater.Dependency, error) {
 	var deps []updater.Dependency
 	for _, instruction := range parsed.AST.Children {
 		// Ignore everything but FROM instructions
-		if instruction.Value != command.From {
+		if !strings.EqualFold(instruction.Value, command.From) {
 			continue
 		}
 
diff --git a/docker/interpolate.go b/docker/interpolate.go
index d38b5e2..4137ee2 100644
--- a/docker/interpolate.go
+++ b/docker/interpolate.go
@@ -21,7 +21,7 @@ func NewInterpolation(parsed *parser.Result) *Interpolation {
 		Vars: map[string]string{},
 	}
 	for _, instruction := range parsed.AST.Children {
-		switch instruction.Value {
+		switch strings.ToLower(instruction.Value) {
 		case command.Arg:
 			varSplit := strings.SplitN(instruction.Next.Value, "=", 2)
 			if len(varSplit) == 2 {