diff --git a/pyocd/debug/rtt.py b/pyocd/debug/rtt.py
index cbd40aa15..d54f2d963 100644
--- a/pyocd/debug/rtt.py
+++ b/pyocd/debug/rtt.py
@@ -409,6 +409,12 @@ def __init__(self, target: SoCTarget, address: int = None,
         if address is None:
             memory_map: MemoryMap = self.target.get_memory_map()
             ram_region: MemoryRegion = memory_map.get_default_region_of_type(MemoryType.RAM)
+            if ram_region is None:
+                ram_region = memory_map.get_first_matching_region(
+                    type=MemoryType.RAM)
+            if ram_region is None:
+                raise exceptions.RTTError(
+                    "No RAM region found for control block search")
 
             self._cb_search_address = ram_region.start
             if size is None: