diff --git a/Cargo.lock b/Cargo.lock
index 2753ca8d09..893876725c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1012,6 +1012,7 @@ dependencies = [
  "hyper",
  "linkerd2-app-core",
  "linkerd2-identity",
+ "linkerd2-io",
  "regex 0.1.80",
  "tokio 0.3.5",
  "tokio-test 0.3.0",
diff --git a/linkerd/app/integration/src/proxy.rs b/linkerd/app/integration/src/proxy.rs
index f340418a90..03accaf2d0 100644
--- a/linkerd/app/integration/src/proxy.rs
+++ b/linkerd/app/integration/src/proxy.rs
@@ -198,6 +198,14 @@ impl Listening {
 }
 
 async fn run(proxy: Proxy, mut env: TestEnv, random_ports: bool) -> Listening {
+    // Logs from spawned threads will not be captured, so use a filter that
+    // disables most of the proxy's logs by default.
+    // TODO(eliza): when we're on Rust 1.49.0+, libtest *will* capture these
+    // logs, so we can use the same default filter as other test code.
+    const DEFAULT_LOG: &'static str = "error,\
+                                       linkerd2_proxy_http=off,\
+                                       linkerd2_proxy_transport=off";
+
     use app::env::Strings;
 
     let controller = if let Some(controller) = proxy.controller {
@@ -291,7 +299,7 @@ async fn run(proxy: Proxy, mut env: TestEnv, random_ports: bool) -> Listening {
     }
 
     let config = app::env::parse_config(&env).unwrap();
-    let (trace, trace_handle) = super::trace_subscriber();
+    let (trace, trace_handle) = super::trace_subscriber(DEFAULT_LOG);
 
     let (running_tx, running_rx) = oneshot::channel();
     let (term_tx, term_rx) = oneshot::channel();
diff --git a/linkerd/app/test/Cargo.toml b/linkerd/app/test/Cargo.toml
index 10a34493b0..37334d7777 100644
--- a/linkerd/app/test/Cargo.toml
+++ b/linkerd/app/test/Cargo.toml
@@ -25,6 +25,7 @@ http-body = "0.4"
 hyper = "0.14.0-dev"
 linkerd2-app-core = { path = "../core", features = ["mock-orig-dst"] }
 linkerd2-identity = { path = "../../identity" }
+linkerd2-io = { path = "../../io", features = ["tokio-test"] }
 regex = "0.1"
 tokio = { version = "0.3", features = ["io-util", "net", "rt", "sync"]}
 tokio-test = "0.3"
diff --git a/linkerd/app/test/src/lib.rs b/linkerd/app/test/src/lib.rs
index 4dbe855dad..b68b330ea3 100644
--- a/linkerd/app/test/src/lib.rs
+++ b/linkerd/app/test/src/lib.rs
@@ -54,13 +54,11 @@ const DEFAULT_LOG: &'static str = "warn,\
                                    linkerd2_proxy_http=error,\
                                    linkerd2_proxy_transport=error";
 
-pub fn trace_subscriber() -> (Dispatch, app_core::trace::Handle) {
+pub fn trace_subscriber(default_filter: &str) -> (Dispatch, app_core::trace::Handle) {
     use std::env;
     let log_level = env::var("LINKERD2_PROXY_LOG")
         .or_else(|_| env::var("RUST_LOG"))
-        .unwrap_or_else(|_| DEFAULT_LOG.to_owned());
-    env::set_var("RUST_LOG", &log_level);
-    env::set_var("LINKERD2_PROXY_LOG", &log_level);
+        .unwrap_or_else(|_| default_filter.to_owned());
     let log_format = env::var("LINKERD2_PROXY_LOG_FORMAT").unwrap_or_else(|_| "PLAIN".to_string());
     env::set_var("LINKERD2_PROXY_LOG_FORMAT", &log_format);
     // This may fail, since the global log compat layer may have been
@@ -74,6 +72,6 @@ pub fn trace_subscriber() -> (Dispatch, app_core::trace::Handle) {
 }
 
 pub fn trace_init() -> tracing::dispatcher::DefaultGuard {
-    let (d, _) = trace_subscriber();
+    let (d, _) = trace_subscriber(DEFAULT_LOG);
     tracing::dispatcher::set_default(&d)
 }