diff --git a/Cargo.lock b/Cargo.lock
index c835244..9ed63f1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2577,7 +2577,7 @@ dependencies = [
 
 [[package]]
 name = "probe"
-version = "0.6.3"
+version = "0.6.4"
 dependencies = [
  "anyhow",
  "clap",
@@ -4653,7 +4653,7 @@ dependencies = [
 
 [[package]]
 name = "website"
-version = "1.3.3"
+version = "1.3.4"
 dependencies = [
  "dotenvy",
  "env_logger",
diff --git a/probe/Cargo.toml b/probe/Cargo.toml
index 7380a9a..80c2568 100644
--- a/probe/Cargo.toml
+++ b/probe/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "probe"
-version = "0.6.3"
+version = "0.6.4"
 edition = "2024"
 license-file = "../LICENSE"
 description = "Dynamic network probe daemon for Cheburcheck"
diff --git a/probe/src/dpi_hop.rs b/probe/src/dpi_hop.rs
index b9fea8d..13a740c 100644
--- a/probe/src/dpi_hop.rs
+++ b/probe/src/dpi_hop.rs
@@ -13,6 +13,7 @@ use std::sync::Arc;
 use std::time::{Duration, Instant};
 
 const PROBE_BYTES: usize = 256;
+const DPI_CLASSIFICATION_DELAY: Duration = Duration::from_millis(100);
 
 #[derive(Debug, Clone)]
 pub struct DpiHopProbeConfig {
@@ -111,6 +112,13 @@ pub fn detect_dpi_hop_blocking(config: DpiHopProbeConfig) -> io::Result<DpiHopPr
             client_hello_bytes = Some(client_hello.len());
         }
         tcp.write_all(&client_hello)?;
+
+        // A blocking DPI may silently discard the ClientHello, so waiting for
+        // a TCP acknowledgement would deadlock the measurement. Give the DPI
+        // a short interval to classify this new flow before sending the
+        // TTL-limited payload instead. This is needed for every attempt because
+        // each TTL deliberately uses a fresh TCP connection.
+        std::thread::sleep(DPI_CLASSIFICATION_DELAY);
         drain_socket(&icmp)?;
 
         let mut payload = [0u8; PROBE_BYTES];
diff --git a/website/Cargo.toml b/website/Cargo.toml
index dd1f98f..373cfc6 100644
--- a/website/Cargo.toml
+++ b/website/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "website"
-version = "1.3.3"
+version = "1.3.4"
 edition = "2024"
 
 [dependencies]