diff --git a/BackgroundProcessing/TranslateUI/Dockerfile b/BackgroundProcessing/TranslateUI/Dockerfile
index bab6309..1af1047 100644
--- a/BackgroundProcessing/TranslateUI/Dockerfile
+++ b/BackgroundProcessing/TranslateUI/Dockerfile
@@ -1,4 +1,4 @@
-FROM mcr.microsoft.com/dotnet/core/aspnet:2.1
+FROM mcr.microsoft.com/dotnet/core/aspnet:3.1
 COPY . /app
 WORKDIR /app
 ENTRYPOINT ["dotnet", "TranslateUI.dll"]
\ No newline at end of file
diff --git a/BackgroundProcessing/TranslateWorker/Dockerfile b/BackgroundProcessing/TranslateWorker/Dockerfile
index 04059fd..8ad9048 100644
--- a/BackgroundProcessing/TranslateWorker/Dockerfile
+++ b/BackgroundProcessing/TranslateWorker/Dockerfile
@@ -1,4 +1,4 @@
-FROM mcr.microsoft.com/dotnet/core/aspnet:2.1
+FROM mcr.microsoft.com/dotnet/core/aspnet:3.1
 COPY . /app
 WORKDIR /app
 ENTRYPOINT ["dotnet", "TranslateWorker.dll"]
\ No newline at end of file
diff --git a/Bookshelf/Dockerfile b/Bookshelf/Dockerfile
index 471606f..bfc21ab 100644
--- a/Bookshelf/Dockerfile
+++ b/Bookshelf/Dockerfile
@@ -1,4 +1,4 @@
-FROM mcr.microsoft.com/dotnet/core/aspnet:2.1
+FROM mcr.microsoft.com/dotnet/core/aspnet:3.1
 COPY . /app
 WORKDIR /app
 ENTRYPOINT ["dotnet", "Bookshelf.dll"]
\ No newline at end of file
diff --git a/HelloWorld/Dockerfile b/HelloWorld/Dockerfile
index 0f26c5f..fa40841 100644
--- a/HelloWorld/Dockerfile
+++ b/HelloWorld/Dockerfile
@@ -1,4 +1,4 @@
-FROM mcr.microsoft.com/dotnet/core/aspnet:2.1
+FROM mcr.microsoft.com/dotnet/core/aspnet:3.1
 COPY . /app
 WORKDIR /app
 ENTRYPOINT ["dotnet", "HelloWorld.dll"]
\ No newline at end of file
diff --git a/Sessions/Dockerfile b/Sessions/Dockerfile
index f5aa4db..fed5790 100644
--- a/Sessions/Dockerfile
+++ b/Sessions/Dockerfile
@@ -1,4 +1,4 @@
-FROM mcr.microsoft.com/dotnet/core/aspnet:2.1
+FROM mcr.microsoft.com/dotnet/core/aspnet:3.1
 COPY . /app
 WORKDIR /app
 ENTRYPOINT ["dotnet", "Sessions.dll"]
\ No newline at end of file