diff --git a/metropolis/build/gotoolwrap/main.go b/metropolis/build/gotoolwrap/main.go
index 3c871c1..d2645ce 100644
--- a/metropolis/build/gotoolwrap/main.go
+++ b/metropolis/build/gotoolwrap/main.go
@@ -136,11 +136,11 @@
 	defer os.RemoveAll(tempDir)
 
 	cmd.Env = append(cmd.Env,
-		fmt.Sprintf("GOROOT=%s", gorootAbs),
-		fmt.Sprintf("GOPATH=%s", gopathAbs),
-		fmt.Sprintf("PATH=%s", path),
-		fmt.Sprintf("GO111MODULE=off"),
-		fmt.Sprintf("GOCACHE=%s", tempDir),
+		"GOROOT=" + gorootAbs,
+		"GOPATH=" + gopathAbs,
+		"PATH=" + path,
+		"GO111MODULE=off",
+		"GOCACHE=" + tempDir,
 	)
 
 	// Run the command interactively.
diff --git a/metropolis/node/core/main.go b/metropolis/node/core/main.go
index ba760f7..9a7e39e 100644
--- a/metropolis/node/core/main.go
+++ b/metropolis/node/core/main.go
@@ -256,7 +256,7 @@
 	crash <- ""
 	crash <- ""
 	crash <- fmt.Sprintf(" Fatal error: %v", err)
-	crash <- fmt.Sprintf(" This node could not be started. Rebooting...")
+	crash <- " This node could not be started. Rebooting..."
 	time.Sleep(time.Second)
 	// Return to minit, which will reboot this node.
 	os.Exit(0)
diff --git a/metropolis/node/kubernetes/apiserver.go b/metropolis/node/kubernetes/apiserver.go
index 7da4490..70c4707 100644
--- a/metropolis/node/kubernetes/apiserver.go
+++ b/metropolis/node/kubernetes/apiserver.go
@@ -179,7 +179,7 @@
 		"--service-account-issuer", "https://metropolis.internal", // TODO: Figure out federation
 		fmt.Sprintf("--service-cluster-ip-range=%v", s.ServiceIPRange.String()),
 		// We use a patch for the allocator that prevents usage of system ports.
-		fmt.Sprintf("--service-node-port-range=1-65535"),
+		"--service-node-port-range=1-65535",
 		args.FileOpt("--tls-cert-file", "server-cert.pem",
 			pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: s.serverCert})),
 		args.FileOpt("--tls-private-key-file", "server-key.pem",
diff --git a/metropolis/pkg/event/etcd/etcd_test.go b/metropolis/pkg/event/etcd/etcd_test.go
index d4eb04f..45b5f98 100644
--- a/metropolis/pkg/event/etcd/etcd_test.go
+++ b/metropolis/pkg/event/etcd/etcd_test.go
@@ -833,8 +833,8 @@
 	res[g.Key] = g.Value
 
 	// These won't be part of the backlog.
-	tc.put(t, ks+"a", fmt.Sprintf("val-100"))
-	tc.put(t, ks+"b", fmt.Sprintf("val-101"))
+	tc.put(t, ks+"a", "val-100")
+	tc.put(t, ks+"b", "val-101")
 
 	// Retrieve the rest of the backlog until BacklogDone is returned.
 	nUpdates := 1