diff --git a/rust/src/core.rs b/rust/src/core.rs
index be164e6734..e448998945 100644
--- a/rust/src/core.rs
+++ b/rust/src/core.rs
@@ -40,6 +40,8 @@ pub const STREAM_TOCLIENT: u8 = 0x08;
 pub const STREAM_GAP:      u8 = 0x10;
 pub const STREAM_DEPTH:    u8 = 0x20;
 pub const STREAM_MIDSTREAM:u8 = 0x40;
+/// stream is async: packets are seen in only one direction.
+pub const STREAM_ASYNC:    u8 = 0x80;
 pub const DIR_BOTH:        u8 = 0b0000_1100;
 const DIR_TOSERVER:        u8 = 0b0000_0100;
 const DIR_TOCLIENT:        u8 = 0b0000_1000;
diff --git a/src/app-layer-parser.c b/src/app-layer-parser.c
index 6cab5fb79f..e7dac6a1cc 100644
--- a/src/app-layer-parser.c
+++ b/src/app-layer-parser.c
@@ -921,7 +921,7 @@ static void AppLayerParserFileTxHousekeeping(
     }
 }
 
-#define IS_DISRUPTED(flags) ((flags) & (STREAM_DEPTH | STREAM_GAP))
+#define IS_DISRUPTED(flags) ((flags) & (STREAM_DEPTH | STREAM_GAP | STREAM_ASYNC))
 
 extern int g_detect_disabled;
 extern bool g_file_logger_enabled;
diff --git a/src/flow.c b/src/flow.c
index d044c1e198..91971c81da 100644
--- a/src/flow.c
+++ b/src/flow.c
@@ -1182,6 +1182,11 @@ uint8_t FlowGetDisruptionFlags(const Flow *f, uint8_t flags)
     if (stream->flags & STREAMTCP_STREAM_FLAG_DEPTH_REACHED) {
         newflags |= STREAM_DEPTH;
     }
+    if (ssn->flags & STREAMTCP_FLAG_ASYNC) {
+        if (stream->tcp_flags == 0) {
+            newflags |= STREAM_ASYNC;
+        }
+    }
     /* todo: handle pass case (also for UDP!) */
 
     return newflags;