diff --git a/services/directory/src/FilterLists.Directory.Api/Dockerfile b/services/directory/src/FilterLists.Directory.Api/Dockerfile
index 22129f997..3c8992ca3 100644
--- a/services/directory/src/FilterLists.Directory.Api/Dockerfile
+++ b/services/directory/src/FilterLists.Directory.Api/Dockerfile
@@ -4,7 +4,7 @@ WORKDIR /app
 EXPOSE 80
 
 # init build
-FROM mcr.microsoft.com/dotnet/core/sdk:3.1-alpine AS build
+FROM mcr.microsoft.com/dotnet/core/sdk:3.1.401-alpine AS build
 
 # restore API
 WORKDIR /src
diff --git a/services/directory/src/FilterLists.Directory.Api/Dockerfile.dev b/services/directory/src/FilterLists.Directory.Api/Dockerfile.dev
index 8d8440fd0..4f415a217 100644
--- a/services/directory/src/FilterLists.Directory.Api/Dockerfile.dev
+++ b/services/directory/src/FilterLists.Directory.Api/Dockerfile.dev
@@ -4,7 +4,7 @@ WORKDIR /app
 EXPOSE 80
 
 # init build
-FROM mcr.microsoft.com/dotnet/core/sdk:3.1-alpine AS build
+FROM mcr.microsoft.com/dotnet/core/sdk:3.1.401-alpine AS build
 
 # restore API
 WORKDIR /src
diff --git a/services/directory/src/FilterLists.Directory.Api/Dockerfile.migrate b/services/directory/src/FilterLists.Directory.Api/Dockerfile.migrate
index 05d6b75f8..dc2ae1293 100644
--- a/services/directory/src/FilterLists.Directory.Api/Dockerfile.migrate
+++ b/services/directory/src/FilterLists.Directory.Api/Dockerfile.migrate
@@ -1,5 +1,5 @@
 # init test-migrations
-FROM mcr.microsoft.com/dotnet/core/sdk:3.1-alpine AS test-migrations
+FROM mcr.microsoft.com/dotnet/core/sdk:3.1.401-alpine AS test-migrations
 ENTRYPOINT ["dotnet", "test", "--logger:trx"]
 
 # restore