diff --git a/initialize/config.go b/initialize/config.go
index 423d4e1..5f5c89b 100644
--- a/initialize/config.go
+++ b/initialize/config.go
@@ -64,17 +64,54 @@ func warnOnUnrecognizedKeys(contents string, warn warner) {
 		}
 	}
 
-	// Finally, check for unrecognized coreos options, if any are set
+	// Check for unrecognized coreos options, if any are set
 	coreos, ok := c["coreos"]
-	if !ok {
-		return
+	if ok {
+		set := coreos.(map[interface{}]interface{})
+		known := cc["coreos"].(map[interface{}]interface{})
+		for k, _ := range set {
+			key := k.(string)
+			if _, ok := known[key]; !ok {
+				warn("Warning: unrecognized key %q in coreos section of provided cloud config - ignoring", key)
+			}
+		}
 	}
-	set := coreos.(map[interface{}]interface{})
-	known := cc["coreos"].(map[interface{}]interface{})
-	for k, _ := range set {
-		key := k.(string)
-		if _, ok := known[key]; !ok {
-			warn("Warning: unrecognized key %q in coreos section of provided cloud config - ignoring", key)
+
+	// Check for any badly-specified users, if any are set
+	users, ok := c["users"]
+	if ok {
+		var known map[string]interface{}
+		b, _ := goyaml.Marshal(&system.User{})
+		goyaml.Unmarshal(b, &known)
+
+		set := users.([]interface{})
+		for _, u := range set {
+			user := u.(map[interface{}]interface{})
+			for k, _ := range user {
+				key := k.(string)
+				if _, ok := known[key]; !ok {
+					warn("Warning: unrecognized key %q in user section of cloud config - ignoring", key)
+				}
+			}
+		}
+	}
+
+	// Check for any badly-specified files, if any are set
+	files, ok := c["write_files"]
+	if ok {
+		var known map[string]interface{}
+		b, _ := goyaml.Marshal(&system.File{})
+		goyaml.Unmarshal(b, &known)
+
+		set := files.([]interface{})
+		for _, f := range set {
+			file := f.(map[interface{}]interface{})
+			for k, _ := range file {
+				key := k.(string)
+				if _, ok := known[key]; !ok {
+					warn("Warning: unrecognized key %q in file section of cloud config - ignoring", key)
+				}
+			}
 		}
 	}
 }
diff --git a/initialize/config_test.go b/initialize/config_test.go
index 51c228b..6db2949 100644
--- a/initialize/config_test.go
+++ b/initialize/config_test.go
@@ -18,6 +18,14 @@ section_unknown:
     something
 bare_unknown:
   bar
+write_files:
+  - content: fun
+    path: /var/party
+    file_unknown: nofun
+users:
+  - name: fry
+    passwd: somehash
+    user_unknown: philip
 hostname:
   foo
 `
@@ -31,6 +39,12 @@ hostname:
 	if len(cfg.Coreos.Etcd) < 1 {
 		t.Fatalf("etcd section not correctly set when invalid keys are present")
 	}
+	if len(cfg.WriteFiles) < 1 || cfg.WriteFiles[0].Content != "fun" || cfg.WriteFiles[0].Path != "/var/party" {
+		t.Fatalf("write_files section not correctly set when invalid keys are present")
+	}
+	if len(cfg.Users) < 1 || cfg.Users[0].Name != "fry" || cfg.Users[0].PasswordHash != "somehash" {
+		t.Fatalf("users section not correctly set when invalid keys are present")
+	}
 
 	var warnings string
 	catchWarn := func(f string, v ...interface{}) {
@@ -48,6 +62,12 @@ hostname:
 	if !strings.Contains(warnings, "section_unknown") {
 		t.Errorf("warnings did not catch unrecognized key section_unknown")
 	}
+	if !strings.Contains(warnings, "user_unknown") {
+		t.Errorf("warnings did not catch unrecognized user key user_unknown")
+	}
+	if !strings.Contains(warnings, "file_unknown") {
+		t.Errorf("warnings did not catch unrecognized file key file_unknown")
+	}
 }
 
 // Assert that the parsing of a cloud config file "generally works"