diff --git a/core/AmArg.cpp b/core/AmArg.cpp
index c5512af0..78b25f21 100644
--- a/core/AmArg.cpp
+++ b/core/AmArg.cpp
@@ -326,3 +326,6 @@ vector<ArgBlob> AmArg::asArgBlobVector() const {
   return res;					
 }			
 
+void AmArg::clear() {
+  invalidate();
+}
diff --git a/core/AmArg.h b/core/AmArg.h
index 4f9ff9ed..49caa4d6 100644
--- a/core/AmArg.h
+++ b/core/AmArg.h
@@ -268,6 +268,8 @@ class AmArg
    *   e.g. "ssif" -> [cstr, cstr, int, double]
    */
   void assertArrayFmt(const char* format) const;
+
+  void clear();
 };
 
 #endif