diff --git a/CHANGELOG.md b/CHANGELOG.md
index feb29d1b484..c235d8887c0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,6 +19,7 @@
 - Retry failing objectstore requests. ([#5836](https://github.com/getsentry/relay/pull/5836))
 - Add mobile normalizations to SpanV2 processing pipeline (mobile tag, main thread, outlier filtering, app start backfill from V1 transactions, device class). ([#5824](https://github.com/getsentry/relay/pull/5824))
 - Remove the deprecated `aiModelCosts` global config, superseded by `aiModelMetadata`. ([#5862](https://github.com/getsentry/relay/pull/5862))
+- Make `_performance_issues_spans` a top-level field. ([#5870](https://github.com/getsentry/relay/pull/5870))
 
 **Bug Fixes**:
 
diff --git a/relay-server/src/processing/legacy_spans/store.rs b/relay-server/src/processing/legacy_spans/store.rs
index 791cde6ba6a..d9b48383b97 100644
--- a/relay-server/src/processing/legacy_spans/store.rs
+++ b/relay-server/src/processing/legacy_spans/store.rs
@@ -23,6 +23,11 @@ macro_rules! required {
 
 /// Converts a [`Span`] into a [`StoreSpanV2`] to be sent to Kafka.
 pub fn convert(span: Annotated<Span>, retentions: Retention) -> Result<Box<StoreSpanV2>> {
+    let performance_issues_spans = span
+        .value()
+        .and_then(|s| s.performance_issues_spans.value().copied())
+        .unwrap_or(false);
+
     let span = span.map_value(relay_spans::span_v1_to_span_v2);
     let span = required!(span);
 
@@ -30,6 +35,7 @@ pub fn convert(span: Annotated<Span>, retentions: Retention) -> Result<Box<Store
         routing_key: span.trace_id.value().copied().map(Into::into),
         retention_days: retentions.standard,
         downsampled_retention_days: retentions.downsampled,
+        performance_issues_spans,
         item: span,
     }))
 }
diff --git a/relay-server/src/processing/spans/store.rs b/relay-server/src/processing/spans/store.rs
index c58884cee28..d7fb7e172ca 100644
--- a/relay-server/src/processing/spans/store.rs
+++ b/relay-server/src/processing/spans/store.rs
@@ -44,6 +44,7 @@ pub fn convert(span: IndexedSpanOnly, ctx: &Context) -> Result<Box<StoreSpanV2>>
         routing_key,
         retention_days: ctx.retention.standard,
         downsampled_retention_days: ctx.retention.downsampled,
+        performance_issues_spans: false,
         item: span,
     }))
 }
diff --git a/relay-server/src/services/store.rs b/relay-server/src/services/store.rs
index 4fba25dbdd3..e7adea9423e 100644
--- a/relay-server/src/services/store.rs
+++ b/relay-server/src/services/store.rs
@@ -137,6 +137,10 @@ pub struct StoreSpanV2 {
     pub retention_days: u16,
     /// Downsampled retention of the span.
     pub downsampled_retention_days: u16,
+    /// Temporary flag controlling where performance issues are detected.
+    ///
+    /// Travels on the Kafka envelope (`SpanMeta`) rather than the SpanV2 body.
+    pub performance_issues_spans: bool,
     /// The final Sentry compatible span item.
     pub item: SpanV2,
 }
@@ -788,6 +792,7 @@ impl StoreService {
             downsampled_retention_days: message.downsampled_retention_days,
             received: datetime_to_timestamp(received_at),
             accepted_outcome_emitted: relay_emits_accepted_outcome,
+            performance_issues_spans: message.performance_issues_spans,
         };
 
         message.try_accept(|span| {
@@ -1677,6 +1682,17 @@ struct SpanMeta {
     downsampled_retention_days: u16,
     /// Indicates whether Relay already emitted an accepted outcome or if EAP still needs to emit it.
     accepted_outcome_emitted: bool,
+    /// Temporary flag that controls where performance issues are detected.
+    ///
+    /// When the flag is set to true, performance issues will be detected on this span provided it
+    /// is a root (segment) instead of the transaction event.
+    ///
+    /// Only set on root spans extracted from transactions.
+    #[serde(
+        rename = "_performance_issues_spans",
+        skip_serializing_if = "std::ops::Not::not"
+    )]
+    performance_issues_spans: bool,
 }
 
 #[derive(Clone, Debug, Serialize)]
diff --git a/relay-spans/src/v1_to_v2.rs b/relay-spans/src/v1_to_v2.rs
index 39a82e9ed89..e1c41c75c52 100644
--- a/relay-spans/src/v1_to_v2.rs
+++ b/relay-spans/src/v1_to_v2.rs
@@ -38,7 +38,7 @@ pub fn span_v1_to_span_v2(span_v1: SpanV1) -> SpanV2 {
         platform,
         was_transaction,
         kind,
-        performance_issues_spans,
+        performance_issues_spans: _, // moved to SpanMeta on the Kafka envelope
         other: _,
     } = span_v1;
 
@@ -55,10 +55,6 @@ pub fn span_v1_to_span_v2(span_v1: SpanV1) -> SpanV2 {
     attributes.insert("sentry.profile_id", profile_id.map_value(|v| v.to_string()));
     attributes.insert("sentry.platform", platform);
     attributes.insert("sentry.was_transaction", was_transaction);
-    attributes.insert(
-        "sentry._internal.performance_issues_spans",
-        performance_issues_spans,
-    );
 
     // Use same precedence as `backfill_data` for data bags:
     if let Some(measurements) = measurements.into_value() {
@@ -371,10 +367,6 @@ mod tests {
               "type": "string",
               "value": "{\"numbers\":[1,2,3]}"
             },
-            "sentry._internal.performance_issues_spans": {
-              "type": "boolean",
-              "value": true
-            },
             "sentry.client_sample_rate": {
               "type": "double",
               "value": 0.11
diff --git a/tests/integration/test_spans.py b/tests/integration/test_spans.py
index 9048e5c0906..0eabc9ac8cf 100644
--- a/tests/integration/test_spans.py
+++ b/tests/integration/test_spans.py
@@ -196,12 +196,7 @@ def test_span_extraction(
     del transaction_span["received"]
 
     if performance_issues_spans:
-        assert (
-            transaction_span["attributes"].pop(
-                "sentry._internal.performance_issues_spans"
-            )["value"]
-            is True
-        )
+        assert transaction_span.pop("_performance_issues_spans") is True
 
     expected_transaction_span = {
         "attributes": {