diff --git a/parsers/survex.py b/parsers/survex.py
index 29cca3c..dd40638 100644
--- a/parsers/survex.py
+++ b/parsers/survex.py
@@ -133,7 +133,7 @@ class LoadingSurvex():
     rx_star    = re.compile(r'(?i)\s*\*[\s,]*(\w+)\s*(.*?)\s*(?:;.*)?$')
     rx_starref = re.compile(r'(?i)^\s*\*ref[\s.:]*((?:19[6789]\d)|(?:20[0123]\d))\s*#?\s*(X)?\s*(.*?\d+.*?)$')
     rx_argsref = re.compile(r'(?i)^[\s.:]*((?:19[6789]\d)|(?:20[0123]\d))\s*#?\s*(X)?\s*(.*?\d+.*?)$')
-    rx_badmerge= re.compile(r'(?i).*(\>\>\>)|(\<\<\<).*$')
+    rx_badmerge= re.compile(r'(?i).*(\>\>\>\>\>)|(\=\=\=\=\=)|(\<\<\<\<\<).*$')
     rx_ref2 = re.compile(r'(?i)\s*ref[.;]?')
     rx_ref3 = re.compile(r'(?i)\s*wallet[.;]?')
 
@@ -1066,6 +1066,7 @@ class LoadingSurvex():
         and reads only the *include and *begin and *end statements. It produces a linearised
         list of the include tree and detects blocks included more than once.
         """
+        thissvxline = 0
         indent = " " * self.depthinclude
         sys.stderr.flush();
         self.callcount +=1
@@ -1092,6 +1093,18 @@ class LoadingSurvex():
         svxlines = fin.read().splitlines()
         for svxline in svxlines:
             self.lineno += 1
+            thissvxline += 1
+            # detect a merge failure inserted by version control
+            mfail = self.rx_badmerge.match(svxline)
+            if mfail: 
+                message = f"\n!! - ERROR version control merge failure\n   - '{svxline}'\n"
+                message = message + f"   - in '{path}' at line {thissvxline}\n"
+                message = message + f"   - line {self.lineno}  {survexblock}\n   - Parsing aborted. NERD++ needed to fix it"
+                print(message)
+                print(message,file=sys.stderr)
+                DataIssue.objects.create(parser='survex', message=message)
+                return # skip this survex file
+
             includestmt =self.rx_include.match(svxline)
             if not includestmt:
                 fcollate.write("{}\n".format(svxline.strip()))