diff --git a/cmd/imageproxy/main.go b/cmd/imageproxy/main.go
index 9d3bcd9..2fea6a7 100644
--- a/cmd/imageproxy/main.go
+++ b/cmd/imageproxy/main.go
@@ -45,6 +45,7 @@ var baseURL = flag.String("baseURL", "", "default base URL for relative remote U
 var cacheDir = flag.String("cacheDir", "", "directory to use for file cache")
 var cacheSize = flag.Uint64("cacheSize", 100, "maximum size of file cache (in MB)")
 var signatureKey = flag.String("signatureKey", "", "HMAC key used in calculating request signatures")
+var scaleUp = flag.Bool("scaleUp", false, "allow images to scale beyond their original dimensions")
 var version = flag.Bool("version", false, "print version information")
 
 func main() {
@@ -90,6 +91,8 @@ func main() {
 		}
 	}
 
+	p.ScaleUp = *scaleUp
+
 	server := &http.Server{
 		Addr:    *addr,
 		Handler: p,
diff --git a/data.go b/data.go
index 406742e..a311505 100644
--- a/data.go
+++ b/data.go
@@ -65,6 +65,9 @@ type Options struct {
 
 	// HMAC Signature for signed requests.
 	Signature string
+
+	// Allow images to scale beyond their original dimensions.
+	ScaleUp bool
 }
 
 var emptyOptions = Options{}
diff --git a/data_test.go b/data_test.go
index e799854..5d63d35 100644
--- a/data_test.go
+++ b/data_test.go
@@ -29,11 +29,11 @@ func TestOptions_String(t *testing.T) {
 			"0x0",
 		},
 		{
-			Options{1, 2, true, 90, true, true, 80, ""},
+			Options{1, 2, true, 90, true, true, 80, "", false},
 			"1x2,fit,r90,fv,fh,q80",
 		},
 		{
-			Options{0.15, 1.3, false, 45, false, false, 95, "c0ffee"},
+			Options{0.15, 1.3, false, 45, false, false, 95, "c0ffee", false},
 			"0.15x1.3,r45,q95,sc0ffee",
 		},
 	}
@@ -82,8 +82,8 @@ func TestParseOptions(t *testing.T) {
 		{"FOO,1,BAR,r90,BAZ", Options{Width: 1, Height: 1, Rotate: 90}},
 
 		// all flags, in different orders
-		{"q70,1x2,fit,r90,fv,fh,sc0ffee", Options{1, 2, true, 90, true, true, 70, "c0ffee"}},
-		{"r90,fh,sc0ffee,q90,1x2,fv,fit", Options{1, 2, true, 90, true, true, 90, "c0ffee"}},
+		{"q70,1x2,fit,r90,fv,fh,sc0ffee", Options{1, 2, true, 90, true, true, 70, "c0ffee", false}},
+		{"r90,fh,sc0ffee,q90,1x2,fv,fit", Options{1, 2, true, 90, true, true, 90, "c0ffee", false}},
 	}
 
 	for _, tt := range tests {
diff --git a/imageproxy.go b/imageproxy.go
index ee000da..9ce9817 100644
--- a/imageproxy.go
+++ b/imageproxy.go
@@ -54,6 +54,9 @@ type Proxy struct {
 
 	// SignatureKey is the HMAC key used to verify signed requests.
 	SignatureKey []byte
+
+	// Allow images to scale beyond their original dimensions.
+	ScaleUp bool
 }
 
 // NewProxy constructs a new proxy.  The provided http RoundTripper will be
@@ -67,17 +70,20 @@ func NewProxy(transport http.RoundTripper, cache Cache) *Proxy {
 		cache = NopCache
 	}
 
+	proxy := Proxy{
+		Cache: cache,
+	}
+
 	client := new(http.Client)
 	client.Transport = &httpcache.Transport{
-		Transport:           &TransformingTransport{transport, client},
+		Transport:           &TransformingTransport{transport, client, &proxy},
 		Cache:               cache,
 		MarkCachedResponses: true,
 	}
 
-	return &Proxy{
-		Client: client,
-		Cache:  cache,
-	}
+	proxy.Client = client
+
+	return &proxy
 }
 
 // ServeHTTP handles image requests.
@@ -232,6 +238,9 @@ type TransformingTransport struct {
 	// used rather than Transport directly in order to ensure that
 	// responses are properly cached.
 	CachingClient *http.Client
+
+	// Proxy is used to access command line flag settings during roundtripping.
+	Proxy *Proxy
 }
 
 // RoundTrip implements the http.RoundTripper interface.
@@ -256,6 +265,12 @@ func (t *TransformingTransport) RoundTrip(req *http.Request) (*http.Response, er
 	}
 
 	opt := ParseOptions(req.URL.Fragment)
+
+	// assign static settings from proxy to options
+	if t.Proxy != nil {
+		opt.ScaleUp = t.Proxy.ScaleUp
+	}
+
 	img, err := Transform(b, opt)
 	if err != nil {
 		glog.Errorf("error transforming image: %v", err)
diff --git a/imageproxy_test.go b/imageproxy_test.go
index 7e27917..7ac5c68 100644
--- a/imageproxy_test.go
+++ b/imageproxy_test.go
@@ -12,6 +12,8 @@ import (
 	"net/url"
 	"strings"
 	"testing"
+
+	"github.com/gregjones/httpcache"
 )
 
 func TestAllowed(t *testing.T) {
@@ -187,6 +189,15 @@ func TestCheck304(t *testing.T) {
 	}
 }
 
+// make sure that the proxy is passed to transport in order
+// to access the command line flags.
+func TestProxyPointer(t *testing.T) {
+	p := NewProxy(nil, nil)
+	if p.Client.Transport.(*httpcache.Transport).Transport.(*TransformingTransport).Proxy != p {
+		t.Errorf("Transport doesnt have proxy pointer")
+	}
+}
+
 // testTransport is an http.RoundTripper that returns certained canned
 // responses for particular requests.
 type testTransport struct{}
@@ -272,7 +283,10 @@ func TestProxy_ServeHTTP_is304(t *testing.T) {
 
 func TestTransformingTransport(t *testing.T) {
 	client := new(http.Client)
-	tr := &TransformingTransport{testTransport{}, client}
+	tr := &TransformingTransport{
+		Transport:     testTransport{},
+		CachingClient: client,
+	}
 	client.Transport = tr
 
 	tests := []struct {
diff --git a/transform.go b/transform.go
index 4302aed..f199eb3 100644
--- a/transform.go
+++ b/transform.go
@@ -102,11 +102,13 @@ func transformImage(m image.Image, opt Options) image.Image {
 	}
 
 	// never resize larger than the original image
-	if w > imgW {
-		w = imgW
-	}
-	if h > imgH {
-		h = imgH
+	if !opt.ScaleUp {
+		if w > imgW {
+			w = imgW
+		}
+		if h > imgH {
+			h = imgH
+		}
 	}
 
 	// resize
diff --git a/transform_test.go b/transform_test.go
index 60efde5..3c4b465 100644
--- a/transform_test.go
+++ b/transform_test.go
@@ -127,6 +127,11 @@ func TestTransformImage(t *testing.T) {
 			Options{Width: 100, Height: 100},
 			ref,
 		},
+		{ // can resize larger than original image
+			ref,
+			Options{Width: 4, Height: 4, ScaleUp: true},
+			newImage(4, 4, red, red, green, green, red, red, green, green, blue, blue, yellow, yellow, blue, blue, yellow, yellow),
+		},
 		{ // invalid values
 			ref,
 			Options{Width: -1, Height: -1},