diff --git a/tests/micropython/heapalloc_str.py b/tests/micropython/heapalloc_str.py
new file mode 100644
index 0000000000..0df39d3c0c
--- /dev/null
+++ b/tests/micropython/heapalloc_str.py
@@ -0,0 +1,14 @@
+# String operations which don't require allocation
+import micropython
+
+micropython.heap_lock()
+
+b"" + b""
+b"" + b"1"
+b"2" + b""
+
+"" + ""
+"" + "1"
+"2" + ""
+
+micropython.heap_unlock()
diff --git a/tests/micropython/heapalloc_str.py.exp b/tests/micropython/heapalloc_str.py.exp
new file mode 100644
index 0000000000..e69de29bb2