diff --git a/C4/SIP/SIPServer.pm b/C4/SIP/SIPServer.pm
index f1c1ae448b..c7aa22297c 100644
--- a/C4/SIP/SIPServer.pm
+++ b/C4/SIP/SIPServer.pm
@@ -344,6 +344,9 @@ sub read_request {
       my $raw_length;
       local $/ = "\015";
 
+      # SIP connections might be active for weeks, clear L1 cache on every request
+      Koha::Caches->flush_L1_caches();
+
     # proper SPEC: (octal) \015 = (hex) x0D = (dec) 13 = (ascii) carriage return
       my $buffer = <STDIN>;
       if ( defined $buffer ) {