diff --git a/docs/Dockerfile b/docs/Dockerfile
index 8b257204..d8463746 100644
--- a/docs/Dockerfile
+++ b/docs/Dockerfile
@@ -1,4 +1,4 @@
-FROM mcr.microsoft.com/dotnet/sdk:7.0 AS builder
+FROM mcr.microsoft.com/dotnet/sdk:9.0 AS builder
 WORKDIR /build
 COPY . /build
 RUN dotnet tool install retypeapp --tool-path /bin