diff --git a/modules/radio.py b/modules/radio.py
index 6bc12c4..f985286 100644
--- a/modules/radio.py
+++ b/modules/radio.py
@@ -436,14 +436,30 @@ def decode_wsjtx_packet(data):
         return None
 
 def check_callsign_match(message, callsigns):
-    """Check if any watched callsign appears in the message"""
+    """Check if any watched callsign appears in the message
+    
+    Uses word boundary matching to avoid false positives like matching
+    'K7' when looking for 'K7MHI'. Callsigns are expected to be
+    separated by spaces or be at the start/end of the message.
+    """
     if not callsigns:
         return True  # If no filter, accept all
     
     message_upper = message.upper()
+    # Split message into words for exact matching
+    words = message_upper.split()
+    
     for callsign in callsigns:
-        if callsign in message_upper:
+        callsign_upper = callsign.upper()
+        # Check if callsign appears as a complete word
+        if callsign_upper in words:
             return True
+        # Also check for callsigns in compound forms like "K7MHI/P" or "K7MHI-7"
+        for word in words:
+            if word.startswith(callsign_upper + '/') or word.startswith(callsign_upper + '-'):
+                return True
+            if word.endswith('/' + callsign_upper) or word.endswith('-' + callsign_upper):
+                return True
     return False
 
 async def wsjtxMonitor():
diff --git a/modules/test_bot.py b/modules/test_bot.py
index 75a1ecc..8e6f188 100644
--- a/modules/test_bot.py
+++ b/modules/test_bot.py
@@ -442,7 +442,13 @@ class TestBot(unittest.TestCase):
         self.assertTrue(check_callsign_match("CQ W1AW FN31", ["K7MHI", "W1AW"]))
         self.assertTrue(check_callsign_match("K7MHI DE W1AW", ["K7MHI", "W1AW"]))
         
-        print("Callsign filtering tests passed")
+        # Test portable/mobile suffixes
+        self.assertTrue(check_callsign_match("CQ K7MHI/P CN87", ["K7MHI"]))
+        self.assertTrue(check_callsign_match("W1AW-7", ["W1AW"]))
+        
+        # Test no false positives with partial matches
+        self.assertFalse(check_callsign_match("CQ K7MHIX CN87", ["K7MHI"]))
+        self.assertFalse(check_callsign_match("K7 TEST", ["K7MHI"]))