diff --git a/src/data.cpp b/src/data.cpp
index d9b49ca..95af43f 100644
--- a/src/data.cpp
+++ b/src/data.cpp
@@ -655,7 +655,10 @@ void Value::copyIn(const void *ptr, StoreType type)
             // assigning variant union.
             auto& val = store->as<Value>();
             if(type==StoreType::Compound) {
-                val = *reinterpret_cast<const Value*>(ptr);
+                auto& newval = *reinterpret_cast<const Value*>(ptr);
+                if(store == newval.store)
+                    throw std::logic_error("Any self-assignment would recurse.  Not allowed.");
+                val = newval;
                 break;
 
             } else {
diff --git a/test/testdata.cpp b/test/testdata.cpp
index 3e9cd31..db3b03b 100644
--- a/test/testdata.cpp
+++ b/test/testdata.cpp
@@ -98,6 +98,24 @@ void testAssignUnion()
     testTrue(val["->"].valid());
 }
 
+void testAssignAny()
+{
+    testDiag("%s", __func__);
+
+    auto val = TypeDef(TypeCode::Any).create();
+
+    // check the simple self assignment is an error.
+    testThrows<std::logic_error>([&val](){
+        val.from(val);
+    });
+
+    val = 42;
+
+    testThrows<std::logic_error>([&val](){
+        val.from(val);
+    });
+}
+
 void testName()
 {
     testDiag("%s", __func__);
@@ -416,11 +434,12 @@ void testClear()
 
 MAIN(testdata)
 {
-    testPlan(146);
+    testPlan(148);
     testSetup();
     testTraverse();
     testAssign();
     testAssignUnion();
+    testAssignAny();
     testName();
     testIterStruct();
     testIterUnion();