diff --git a/lib/handlebars/compiler/compiler.js b/lib/handlebars/compiler/compiler.js
index 4580f31c..12f16958 100644
--- a/lib/handlebars/compiler/compiler.js
+++ b/lib/handlebars/compiler/compiler.js
@@ -168,26 +168,43 @@ Handlebars.JavaScriptCompiler = function() {};
     },
 
     mustache: function(mustache) {
-      var id = mustache.id;
+      var isHelper   = mustache.isHelper;
+      var isEligible = mustache.eligibleHelper;
+      var options    = this.options;
 
-      if (!mustache.eligibleHelper) {
-        this.simpleMustache(mustache);
-      } else if (mustache.isHelper) {
-        this.helperMustache(mustache);
-      } else {
-        var params = this.setupStackForMustache(mustache),
-            name = id.parts[0];
+      // if ambiguous, we can possibly resolve the ambiguity now
+      if (isEligible && !isHelper) {
+        var name = mustache.id.parts[0];
 
-        this.opcode('invokeMustache', params.length, mustache.id.original);
+        if (options.knownHelpers[name]) {
+          isHelper = true;
+        } else if (options.knownHelpersOnly) {
+          isEligible = false;
+        }
       }
 
-      if(mustache.escaped && !this.options.noEscape) {
+      if (!isEligible) {
+        this.simpleMustache(mustache);
+      } else if (isHelper) {
+        this.helperMustache(mustache);
+      } else {
+        this.ambiguousMustache(mustache);
+      }
+
+      if(mustache.escaped && !options.noEscape) {
         this.opcode('appendEscaped');
       } else {
         this.opcode('append');
       }
     },
 
+    ambiguousMustache: function(mustache) {
+      var params = this.setupStackForMustache(mustache),
+          id = mustache.id, name = id.parts[0];
+
+      this.opcode('invokeMustache', params.length, id.original);
+    },
+
     simpleMustache: function(mustache) {
       var id = mustache.id;