diff --git a/esphome/components/api/proto.h b/esphome/components/api/proto.h
index be87dac6f6..9666b7e9ff 100644
--- a/esphome/components/api/proto.h
+++ b/esphome/components/api/proto.h
@@ -105,7 +105,7 @@ class ProtoVarInt {
 
   /// Parse a varint from buffer. consumed must be a valid pointer (not null).
   static optional<ProtoVarInt> parse(const uint8_t *buffer, uint32_t len, uint32_t *consumed) {
-#ifdef DEBUG
+#ifdef ESPHOME_DEBUG_API
     assert(consumed != nullptr);
 #endif
     if (len == 0)
@@ -922,7 +922,7 @@ inline void ProtoWriteBuffer::encode_message(uint32_t field_id, const ProtoMessa
   // Now encode the message content - it will append to the buffer
   value.encode(*this);
 
-#ifdef DEBUG
+#ifdef ESPHOME_DEBUG_API
   // Verify that the encoded size matches what we calculated
   assert(this->buffer_->size() == begin + varint_length_bytes + msg_length_bytes);
 #endif
diff --git a/esphome/core/defines.h b/esphome/core/defines.h
index 0c888933bf..a2a967985e 100644
--- a/esphome/core/defines.h
+++ b/esphome/core/defines.h
@@ -14,6 +14,7 @@
 #define ESPHOME_PROJECT_VERSION_30 "v2"
 #define ESPHOME_VARIANT "ESP32"
 #define ESPHOME_DEBUG_SCHEDULER
+#define ESPHOME_DEBUG_API
 
 // Default threading model for static analysis (ESP32 is multi-threaded with atomics)
 #define ESPHOME_THREAD_MULTI_ATOMICS
diff --git a/tests/integration/conftest.py b/tests/integration/conftest.py
index 50e8d4122b..36df1bc83e 100644
--- a/tests/integration/conftest.py
+++ b/tests/integration/conftest.py
@@ -197,6 +197,7 @@ async def yaml_config(request: pytest.FixtureRequest, unused_tcp_port: int) -> s
             "  platformio_options:\n"
             "    build_flags:\n"
             '      - "-DDEBUG"  # Enable assert() statements\n'
+            '      - "-DESPHOME_DEBUG_API"  # Enable API protocol asserts\n'
             '      - "-g"       # Add debug symbols',
         )