diff --git a/src/main/java/seedu/address/logic/injector/NavigationInjector.java b/src/main/java/seedu/address/logic/injector/NavigationInjector.java
index 3335f3097ed..7303c9c2853 100644
--- a/src/main/java/seedu/address/logic/injector/NavigationInjector.java
+++ b/src/main/java/seedu/address/logic/injector/NavigationInjector.java
@@ -27,33 +27,39 @@ public class NavigationInjector extends Injector {
     public String inject(String commandText, Model model) {
         final Matcher matcher = TrackerParser.BASIC_COMMAND_FORMAT.matcher(commandText.trim());
 
-        // If input does not match syntax, return unmodified user input.
-        if (!matcher.matches()) {
+        if (shouldIgnoreCommand(matcher)) {
             return commandText;
         }
 
-        final String commandWord = matcher.group("commandWord");
+        final String arguments = matcher.group("arguments");
 
-        // If command is whitelisted, return unmodified user input.
-        if (isCommandWhitelisted(commandWord)) {
-            return commandText;
+        commandText = removeRootPrefix(commandText);
+        return injectMissingArgs(commandText, arguments, model).trim();
+    }
+
+    private boolean shouldIgnoreCommand(Matcher matcher) {
+        if (!matcher.matches()) {
+            return true;
         }
 
-        final String arguments = matcher.group("arguments");
+        final String commandWord = matcher.group("commandWord");
+        if (isCommandWhitelisted(commandWord) || !isValidCommandWord(commandWord)) {
+            return true;
+        }
+
+        return false;
+    }
+
+    private String injectMissingArgs(String commandText, String arguments, Model model) {
+        NavigationContext navContext = model.getCurrentNavContext();
 
         ArgumentMultimap argMultimap =
                 ArgumentTokenizer.tokenize(arguments, PREFIX_ROOT, PREFIX_MODULE, PREFIX_LECTURE);
-        NavigationContext navContext = model.getCurrentNavContext();
-        return injectMissingArgs(commandText, argMultimap, navContext).trim();
-    }
 
-    private String injectMissingArgs(String commandText, ArgumentMultimap argMultimap, NavigationContext navContext) {
         boolean hasRootPrefix = argMultimap.getValue(PREFIX_ROOT).isPresent();
         boolean hasLecturePrefix = argMultimap.getValue(PREFIX_LECTURE).isPresent();
         boolean hasModulePrefix = argMultimap.getValue(PREFIX_MODULE).isPresent();
 
-        commandText = removeRootPrefix(commandText);
-
         // Don't inject context prefixes if only root prefix present.
         if (hasRootPrefix && !hasLecturePrefix) {
             return commandText;
@@ -82,6 +88,10 @@ private String injectLecturePrefixArg(String commandText, NavigationContext navC
         return commandText + " " + navContext.getLecturePrefixArg();
     }
 
+    private boolean isValidCommandWord(String commandWord) {
+        return !commandWord.matches(PREFIX_ROOT.toString());
+    }
+
     private boolean isCommandWhitelisted(String commandWord) {
         for (var w : WHITELIST) {
             if (commandWord.equals(w)) {