diff --git a/packagers/jam.go b/packagers/jam.go
index fc3a1af..373281a 100644
--- a/packagers/jam.go
+++ b/packagers/jam.go
@@ -106,11 +106,21 @@ func (j Jam) Execute(buildpackDir, output, version string, offline bool) error {
 
 	}
 
-	args = []string{
-		"buildpack", "package",
-		output,
-		"--format", "file",
-		"--target", fmt.Sprintf("linux/%s", runtime.GOARCH),
+	if ( command == "--buildpack") {
+		args = []string{
+			"buildpack", "package",
+			output,
+			"--format", "file",
+			"--target", fmt.Sprintf("linux/%s", runtime.GOARCH),
+		}
+	} else {
+		// pack extension does not yet support multi-arch
+		// update to inclue --target once it does
+		args = []string{
+			"extension", "package",
+			output,
+			"--format", "file",
+		}
 	}
 
 	err = j.pack.Execute(pexec.Execution{
diff --git a/packagers/jam_test.go b/packagers/jam_test.go
index 381aeb4..10a9a26 100644
--- a/packagers/jam_test.go
+++ b/packagers/jam_test.go
@@ -109,10 +109,9 @@ func testJam(t *testing.T, context spec.G, it spec.S) {
 				}))
 
 				Expect(pack.ExecuteCall.Receives.Execution.Args).To(Equal([]string{
-					"buildpack", "package",
+					"extension", "package",
 					"some-output",
 					"--format", "file",
-					"--target", fmt.Sprintf("linux/%s", runtime.GOARCH),
 				}))
 			})
 		})