diff --git a/C4/SIP/SIPServer.pm b/C4/SIP/SIPServer.pm
index 5801db7c03..0939478349 100644
--- a/C4/SIP/SIPServer.pm
+++ b/C4/SIP/SIPServer.pm
@@ -588,8 +588,11 @@ sub read_request {
         $raw_length = length $buffer;
         $buffer =~ s/^\s*[^A-z0-9]+//s;
 
-        # Every line must start with a "real" character.  Not whitespace, control chars, etc.
-        $buffer =~ s/[^A-z0-9]+$//s;
+        # Remove leading/trailing control characters and whitespace.
+        # SIP2 messages should be a single printable line; this defensively
+        # cleans up stray CR/LF or junk from buggy or long-lived client connections.
+        $buffer =~ s/^[[:cntrl:]\s]+//;
+        $buffer =~ s/[[:cntrl:]\s]+$//;
 
         # Same for the end.  Note this catches the problem some clients have sending empty fields at the end, like |||
         $buffer =~ s/\015?\012//g;     # Extra line breaks must die