diff --git a/src/core/config/platform.h b/src/core/config/platform.h
index 35b820755..2f3e4a093 100644
--- a/src/core/config/platform.h
+++ b/src/core/config/platform.h
@@ -107,4 +107,15 @@
 #define OPENTHREAD_CONFIG_PLATFORM_RADIO_COEX_ENABLE 0
 #endif
 
+/**
+ * @def OPENTHREAD_CONFIG_PLATFORM_RADIO_SPINEL_RX_FRAME_BUFFER_SIZE
+ *
+ * Specifies the rx frame buffer size used by `SpinelInterface` in RCP host (posix) code. This is applicable/used when
+ * `RadioSpinel` platform is used.
+ *
+ */
+#ifndef OPENTHREAD_CONFIG_PLATFORM_RADIO_SPINEL_RX_FRAME_BUFFER_SIZE
+#define OPENTHREAD_CONFIG_PLATFORM_RADIO_SPINEL_RX_FRAME_BUFFER_SIZE 8192
+#endif
+
 #endif // CONFIG_PLATFORM_H_
diff --git a/src/lib/spinel/spinel_interface.hpp b/src/lib/spinel/spinel_interface.hpp
index 950f09ffa..585f257aa 100644
--- a/src/lib/spinel/spinel_interface.hpp
+++ b/src/lib/spinel/spinel_interface.hpp
@@ -45,7 +45,7 @@ class SpinelInterface
 public:
     enum
     {
-        kMaxFrameSize = 2048, ///< Maximum frame size (number of bytes).
+        kMaxFrameSize = OPENTHREAD_CONFIG_PLATFORM_RADIO_SPINEL_RX_FRAME_BUFFER_SIZE, ///< Maximum buffer size.
     };
 
     /**