diff --git a/extras/build-tests/nix/build b/extras/build-tests/nix/build
index 3cced367e..14e2123f9 100755
--- a/extras/build-tests/nix/build
+++ b/extras/build-tests/nix/build
@@ -17,7 +17,7 @@ else
 fi
 
 # -DRAWCMDLOGGING was dropped, but can be useful for debugging
-export CPPFLAGS="$CPPFLAGS -DFAKELAG_CONFIGURABLE -DNOREMOVETMP"
+export CPPFLAGS="$CPPFLAGS -DFAKELAG_CONFIGURABLE -DNOREMOVETMP -DTESTSUITE"
 
 # !! skipped for now: extras/build-tests/nix/select-config $BUILDCONFIG !!
 # !! temporary use this:
diff --git a/src/modules/chanmodes/floodprot.c b/src/modules/chanmodes/floodprot.c
index 7c50f8e9b..2f962dc43 100644
--- a/src/modules/chanmodes/floodprot.c
+++ b/src/modules/chanmodes/floodprot.c
@@ -1205,6 +1205,12 @@ int cmodef_channel_create(Channel *channel)
 	ChannelFloodProtection *base;
 	ChannelFloodProtection *fld;
 
+#ifdef TESTSUITE
+	/* Sync channels for the test suite are exempt */
+	if (!strncasecmp(channel->name, "#__SYNC__", 9))
+		return 0;
+#endif
+
 	if (!cfg.default_profile)
 		return 0;