diff --git a/pyproject.toml b/pyproject.toml
index 7fd8ae1a..201fc8b1 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -23,20 +23,20 @@ classifiers = [
 dependencies = [
     "azure-core<2.0.0,>=1.28.0",
     "azure-core-tracing-opentelemetry~=1.0.0b11",
-    "azure-monitor-opentelemetry-exporter~=1.0.0b53",
-    "opentelemetry-sdk==1.40",
-    "opentelemetry-api==1.40",
-    "opentelemetry-exporter-otlp-proto-http==1.40",
-    "opentelemetry-instrumentation==0.61b0",
-    "opentelemetry-instrumentation-django==0.61b0",
-    "opentelemetry-instrumentation-fastapi==0.61b0",
-    "opentelemetry-instrumentation-flask==0.61b0",
-    "opentelemetry-instrumentation-httpx==0.61b0",
-    "opentelemetry-instrumentation-psycopg2==0.61b0",
-    "opentelemetry-instrumentation-requests==0.61b0",
-    "opentelemetry-instrumentation-urllib==0.61b0",
-    "opentelemetry-instrumentation-urllib3==0.61b0",
-    "opentelemetry-instrumentation-logging==0.61b0",
+    "azure-monitor-opentelemetry-exporter~=1.0.0b54",
+    "opentelemetry-sdk~=1.43.0",
+    "opentelemetry-api~=1.43.0",
+    "opentelemetry-exporter-otlp-proto-http~=1.43.0",
+    "opentelemetry-instrumentation>=0.64b0,<0.65b0",
+    "opentelemetry-instrumentation-django>=0.64b0,<0.65b0",
+    "opentelemetry-instrumentation-fastapi>=0.64b0,<0.65b0",
+    "opentelemetry-instrumentation-flask>=0.64b0,<0.65b0",
+    "opentelemetry-instrumentation-httpx>=0.64b0,<0.65b0",
+    "opentelemetry-instrumentation-psycopg2>=0.64b0,<0.65b0",
+    "opentelemetry-instrumentation-requests>=0.64b0,<0.65b0",
+    "opentelemetry-instrumentation-urllib>=0.64b0,<0.65b0",
+    "opentelemetry-instrumentation-urllib3>=0.64b0,<0.65b0",
+    "opentelemetry-instrumentation-logging>=0.64b0,<0.65b0",
     "opentelemetry-instrumentation-openai-agents-v2==0.1.0",
     "opentelemetry-instrumentation-openai-v2==2.3b0",
     "opentelemetry-resource-detector-azure<1.0.0,>=0.1.5",
diff --git a/src/microsoft/opentelemetry/_genai/main_agent/_processor.py b/src/microsoft/opentelemetry/_genai/main_agent/_processor.py
index 5cb098a1..7c24a644 100644
--- a/src/microsoft/opentelemetry/_genai/main_agent/_processor.py
+++ b/src/microsoft/opentelemetry/_genai/main_agent/_processor.py
@@ -28,6 +28,7 @@
 from opentelemetry.sdk.trace import ReadableSpan, Span
 from opentelemetry.sdk.trace.export import SpanProcessor
 from opentelemetry.trace import Span as SpanAPI
+from opentelemetry.util.types import AttributeValue
 
 # Each row: (target attribute on current span,
 #            primary source attribute on parent span,
@@ -108,15 +109,16 @@ def on_end(self, span: ReadableSpan) -> None:
         if mutable is None:
             return
 
+        # Build the attributes to write before touching the (now frozen) span.
+        updates: dict[str, AttributeValue] = {}
+
         # Self-promotion: top-level invoke_agent spans copy their own
         # gen_ai.agent.* → microsoft.gen_ai.main_agent.*
         if attributes.get(GEN_AI_OPERATION_NAME_KEY) == INVOKE_AGENT_OPERATION_NAME:
             for target, source in _SELF_COPY_TABLE:
                 value = attributes.get(source)
                 if value is not None:
-                    mutable[target] = value
-            return
-
+                    updates[target] = value
         # Fallback propagation: re-read from the parent span whose attributes
         # may have been set after this child was created (timing issue).
         if parent is not None:
@@ -126,7 +128,26 @@ def on_end(self, span: ReadableSpan) -> None:
                 if value is None:
                     value = parent_attributes.get(fallback)
                 if value is not None:
+                    updates[target] = value
+
+        if not updates:
+            return
+
+        # OTel SDK >= 1.43 freezes span attributes (``_immutable = True``) inside
+        # ``end()`` *before* invoking ``on_end``.  Writing then raises ``TypeError``.
+        # Temporarily lift the freeze for our own synchronous writes and always
+        # restore it so the exported ``ReadableSpan`` snapshot stays frozen.
+        was_immutable = getattr(mutable, "_immutable", False)
+        if was_immutable:
+            mutable._immutable = False  # pylint: disable=protected-access
+            try:
+                for target, value in updates.items():
                     mutable[target] = value
+            finally:
+                mutable._immutable = True  # pylint: disable=protected-access
+        else:
+            for target, value in updates.items():
+                mutable[target] = value
 
     def shutdown(self) -> None:
         self._parent_spans.clear()