diff --git a/examples/common/font/text_buffer_manager.cpp b/examples/common/font/text_buffer_manager.cpp
index 4493e3b1..cc7eacc8 100644
--- a/examples/common/font/text_buffer_manager.cpp
+++ b/examples/common/font/text_buffer_manager.cpp
@@ -793,10 +793,12 @@ void TextBufferManager::submitTextBuffer(TextBufferHandle _handle, uint8_t _id,
 				vbh.idx = bc.vertexBufferHandleIdx;
 
 				bgfx::updateDynamicIndexBuffer(ibh
+						, 0
 						, bgfx::copy(bc.textBuffer->getIndexBuffer(), indexSize)
 						);
 
 				bgfx::updateDynamicVertexBuffer(vbh
+						, 0
 						, bgfx::copy(bc.textBuffer->getVertexBuffer(), vertexSize)
 						);
 			}
diff --git a/include/bgfx.c99.h b/include/bgfx.c99.h
index 91b8a5be..2b48cc22 100644
--- a/include/bgfx.c99.h
+++ b/include/bgfx.c99.h
@@ -482,7 +482,7 @@ BGFX_C_API bgfx_dynamic_index_buffer_handle_t bgfx_create_dynamic_index_buffer(u
 BGFX_C_API bgfx_dynamic_index_buffer_handle_t bgfx_create_dynamic_index_buffer_mem(const bgfx_memory_t* _mem, uint16_t _flags);
 
 /**/
-BGFX_C_API void bgfx_update_dynamic_index_buffer(bgfx_dynamic_index_buffer_handle_t _handle, const bgfx_memory_t* _mem);
+BGFX_C_API void bgfx_update_dynamic_index_buffer(bgfx_dynamic_index_buffer_handle_t _handle, uint32_t _startIndex, const bgfx_memory_t* _mem);
 
 /**/
 BGFX_C_API void bgfx_destroy_dynamic_index_buffer(bgfx_dynamic_index_buffer_handle_t _handle);
@@ -494,7 +494,7 @@ BGFX_C_API bgfx_dynamic_vertex_buffer_handle_t bgfx_create_dynamic_vertex_buffer
 BGFX_C_API bgfx_dynamic_vertex_buffer_handle_t bgfx_create_dynamic_vertex_buffer_mem(const bgfx_memory_t* _mem, const bgfx_vertex_decl_t* _decl, uint16_t _flags);
 
 /**/
-BGFX_C_API void bgfx_update_dynamic_vertex_buffer(bgfx_dynamic_vertex_buffer_handle_t _handle, const bgfx_memory_t* _mem);
+BGFX_C_API void bgfx_update_dynamic_vertex_buffer(bgfx_dynamic_vertex_buffer_handle_t _handle, uint32_t _startVertex, const bgfx_memory_t* _mem);
 
 /**/
 BGFX_C_API void bgfx_destroy_dynamic_vertex_buffer(bgfx_dynamic_vertex_buffer_handle_t _handle);
diff --git a/include/bgfx.h b/include/bgfx.h
index 82faf053..c4986e47 100644
--- a/include/bgfx.h
+++ b/include/bgfx.h
@@ -776,11 +776,12 @@ namespace bgfx
 	/// Update dynamic index buffer.
 	///
 	/// @param _handle Dynamic index buffer handle.
+	/// @param _startIndex Start index.
 	/// @param _mem Index buffer data.
 	///
 	/// @attention C99 equivalent is `bgfx_update_dynamic_index_buffer`.
 	///
-	void updateDynamicIndexBuffer(DynamicIndexBufferHandle _handle, const Memory* _mem);
+	void updateDynamicIndexBuffer(DynamicIndexBufferHandle _handle, uint32_t _startIndex, const Memory* _mem);
 
 	/// Destroy dynamic index buffer.
 	///
@@ -834,9 +835,13 @@ namespace bgfx
 
 	/// Update dynamic vertex buffer.
 	///
+	/// @param _handle Dynamic vertex buffer handle.
+	/// @param _startVertex Start vertex.
+	/// @param _mem Vertex buffer data.
+	///
 	/// @attention C99 equivalent is `bgfx_update_dynamic_vertex_buffer`.
 	///
-	void updateDynamicVertexBuffer(DynamicVertexBufferHandle _handle, const Memory* _mem);
+	void updateDynamicVertexBuffer(DynamicVertexBufferHandle _handle, uint32_t _startVertex, const Memory* _mem);
 
 	/// Destroy dynamic vertex buffer.
 	///
diff --git a/src/bgfx.cpp b/src/bgfx.cpp
index c48f540c..854e807b 100644
--- a/src/bgfx.cpp
+++ b/src/bgfx.cpp
@@ -2220,11 +2220,11 @@ again:
 		return s_ctx->createDynamicIndexBuffer(_mem, _flags);
 	}
 
-	void updateDynamicIndexBuffer(DynamicIndexBufferHandle _handle, const Memory* _mem)
+	void updateDynamicIndexBuffer(DynamicIndexBufferHandle _handle, uint32_t _startIndex, const Memory* _mem)
 	{
 		BGFX_CHECK_MAIN_THREAD();
 		BX_CHECK(NULL != _mem, "_mem can't be NULL");
-		s_ctx->updateDynamicIndexBuffer(_handle, _mem);
+		s_ctx->updateDynamicIndexBuffer(_handle, _startIndex, _mem);
 	}
 
 	void destroyDynamicIndexBuffer(DynamicIndexBufferHandle _handle)
@@ -2248,11 +2248,11 @@ again:
 		return s_ctx->createDynamicVertexBuffer(_mem, _decl, _flags);
 	}
 
-	void updateDynamicVertexBuffer(DynamicVertexBufferHandle _handle, const Memory* _mem)
+	void updateDynamicVertexBuffer(DynamicVertexBufferHandle _handle, uint32_t _startVertex, const Memory* _mem)
 	{
 		BGFX_CHECK_MAIN_THREAD();
 		BX_CHECK(NULL != _mem, "_mem can't be NULL");
-		s_ctx->updateDynamicVertexBuffer(_handle, _mem);
+		s_ctx->updateDynamicVertexBuffer(_handle, _startVertex, _mem);
 	}
 
 	void destroyDynamicVertexBuffer(DynamicVertexBufferHandle _handle)
@@ -3342,10 +3342,10 @@ BGFX_C_API bgfx_dynamic_index_buffer_handle_t bgfx_create_dynamic_index_buffer_m
 	return handle.c;
 }
 
-BGFX_C_API void bgfx_update_dynamic_index_buffer(bgfx_dynamic_index_buffer_handle_t _handle, const bgfx_memory_t* _mem)
+BGFX_C_API void bgfx_update_dynamic_index_buffer(bgfx_dynamic_index_buffer_handle_t _handle, uint32_t _startIndex, const bgfx_memory_t* _mem)
 {
 	union { bgfx_dynamic_index_buffer_handle_t c; bgfx::DynamicIndexBufferHandle cpp; } handle = { _handle };
-	bgfx::updateDynamicIndexBuffer(handle.cpp, (const bgfx::Memory*)_mem);
+	bgfx::updateDynamicIndexBuffer(handle.cpp, _startIndex, (const bgfx::Memory*)_mem);
 }
 
 BGFX_C_API void bgfx_destroy_dynamic_index_buffer(bgfx_dynamic_index_buffer_handle_t _handle)
@@ -3370,10 +3370,10 @@ BGFX_C_API bgfx_dynamic_vertex_buffer_handle_t bgfx_create_dynamic_vertex_buffer
 	return handle.c;
 }
 
-BGFX_C_API void bgfx_update_dynamic_vertex_buffer(bgfx_dynamic_vertex_buffer_handle_t _handle, const bgfx_memory_t* _mem)
+BGFX_C_API void bgfx_update_dynamic_vertex_buffer(bgfx_dynamic_vertex_buffer_handle_t _handle, uint32_t _startVertex, const bgfx_memory_t* _mem)
 {
 	union { bgfx_dynamic_vertex_buffer_handle_t c; bgfx::DynamicVertexBufferHandle cpp; } handle = { _handle };
-	bgfx::updateDynamicVertexBuffer(handle.cpp, (const bgfx::Memory*)_mem);
+	bgfx::updateDynamicVertexBuffer(handle.cpp, _startVertex, (const bgfx::Memory*)_mem);
 }
 
 BGFX_C_API void bgfx_destroy_dynamic_vertex_buffer(bgfx_dynamic_vertex_buffer_handle_t _handle)
diff --git a/src/bgfx_p.h b/src/bgfx_p.h
index 1156740e..97621d31 100644
--- a/src/bgfx_p.h
+++ b/src/bgfx_p.h
@@ -2159,12 +2159,12 @@ namespace bgfx
 			DynamicIndexBufferHandle handle = createDynamicIndexBuffer(_mem->size/indexSize, _flags);
 			if (isValid(handle) )
 			{
-				updateDynamicIndexBuffer(handle, _mem);
+				updateDynamicIndexBuffer(handle, 0, _mem);
 			}
 			return handle;
 		}
 
-		BGFX_API_FUNC(void updateDynamicIndexBuffer(DynamicIndexBufferHandle _handle, const Memory* _mem) )
+		BGFX_API_FUNC(void updateDynamicIndexBuffer(DynamicIndexBufferHandle _handle, uint32_t _startIndex, const Memory* _mem) )
 		{
 			BGFX_CHECK_HANDLE("updateDynamicIndexBuffer", m_dynamicIndexBufferHandle, _handle);
 
@@ -2185,8 +2185,8 @@ namespace bgfx
 				dib.m_startIndex = bx::strideAlign(dib.m_offset, indexSize)/indexSize;
 			}
 
-			uint32_t offset = dib.m_startIndex*indexSize;
-			uint32_t size   = bx::uint32_min(dib.m_size, _mem->size);
+			uint32_t offset = (dib.m_startIndex + _startIndex)*indexSize;
+			uint32_t size   = bx::uint32_min(bx::uint32_satsub(dib.m_size, _startIndex*indexSize), _mem->size);
 			BX_CHECK(_mem->size <= size, "Truncating dynamic index buffer update (size %d, mem size %d)."
 				, size
 				, _mem->size
@@ -2308,12 +2308,12 @@ namespace bgfx
 			DynamicVertexBufferHandle handle = createDynamicVertexBuffer(uint16_t(numVertices), _decl, _flags);
 			if (isValid(handle) )
 			{
-				updateDynamicVertexBuffer(handle, _mem);
+				updateDynamicVertexBuffer(handle, 0, _mem);
 			}
 			return handle;
 		}
 
-		BGFX_API_FUNC(void updateDynamicVertexBuffer(DynamicVertexBufferHandle _handle, const Memory* _mem) )
+		BGFX_API_FUNC(void updateDynamicVertexBuffer(DynamicVertexBufferHandle _handle, uint32_t _startVertex, const Memory* _mem) )
 		{
 			BGFX_CHECK_HANDLE("updateDynamicVertexBuffer", m_dynamicVertexBufferHandle, _handle);
 
@@ -2333,8 +2333,8 @@ namespace bgfx
 				dvb.m_startVertex = bx::strideAlign(dvb.m_offset, dvb.m_stride)/dvb.m_stride;
 			}
 
-			uint32_t offset = dvb.m_startVertex*dvb.m_stride;
-			uint32_t size   = bx::uint32_min(dvb.m_size, _mem->size);
+			uint32_t offset = (dvb.m_startVertex + _startVertex)*dvb.m_stride;
+			uint32_t size   = bx::uint32_min(bx::uint32_satsub(dvb.m_size, _startVertex*dvb.m_stride), _mem->size);
 			BX_CHECK(_mem->size <= size, "Truncating dynamic vertex buffer update (size %d, mem size %d)."
 				, dvb.m_size
 				, _mem->size