diff --git a/.github/workflows/ci-api.yml b/.github/workflows/ci-api.yml
index ab2f915b8..a73e1f588 100644
--- a/.github/workflows/ci-api.yml
+++ b/.github/workflows/ci-api.yml
@@ -11,6 +11,8 @@ on:
 
 env:
   SCHEME: scheme
+  IDRIS2_TESTS_CG: chez
+
 jobs:
   build:
     runs-on: ubuntu-latest
diff --git a/.github/workflows/ci-macos.yml b/.github/workflows/ci-macos.yml
index b8d2be1d4..23e0cb4d7 100644
--- a/.github/workflows/ci-macos.yml
+++ b/.github/workflows/ci-macos.yml
@@ -10,6 +10,8 @@ on:
       - master
 env:
   SCHEME: chez
+  IDRIS2_TESTS_CG: chez
+
 jobs:
   build:
     runs-on: macos-latest
diff --git a/.github/workflows/ci-ubuntu-racket.yml b/.github/workflows/ci-ubuntu-racket.yml
index 58720c284..a83159439 100644
--- a/.github/workflows/ci-ubuntu-racket.yml
+++ b/.github/workflows/ci-ubuntu-racket.yml
@@ -9,6 +9,9 @@ on:
     branches:
       - master
 
+env:
+  IDRIS2_TESTS_CG: racket
+
 jobs:
   build:
     runs-on: ubuntu-latest
@@ -17,9 +20,8 @@ jobs:
         uses: actions/checkout@v2
       - name: Install build dependencies
         run: |
-          sudo apt-get update 
+          sudo apt-get update
           sudo apt-get install -y racket
       - name: Build from bootstrap
         run: make bootstrap-racket
         shell: bash
-
diff --git a/.github/workflows/ci-ubuntu.yml b/.github/workflows/ci-ubuntu.yml
index 0a2934a0d..2464ca57f 100644
--- a/.github/workflows/ci-ubuntu.yml
+++ b/.github/workflows/ci-ubuntu.yml
@@ -11,6 +11,8 @@ on:
 
 env:
   SCHEME: scheme
+  IDRIS2_TESTS_CG: chez
+
 jobs:
   build:
     runs-on: ubuntu-latest
@@ -27,4 +29,3 @@ jobs:
       - name: Build and test self-hosted
         run: make clean && make all && make test INTERACTIVE=''
         shell: bash
-
diff --git a/.github/workflows/ci-windows.yml b/.github/workflows/ci-windows.yml
index f0942d6ed..dff064c01 100644
--- a/.github/workflows/ci-windows.yml
+++ b/.github/workflows/ci-windows.yml
@@ -12,6 +12,7 @@ env:
   MSYSTEM: MINGW64
   MSYS2_PATH_TYPE: inherit
   SCHEME: scheme
+  IDRIS2_TESTS_CG: chez
   CC: gcc
 
 jobs:
@@ -24,7 +25,7 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v2
       - name: Get Chez Scheme
-        run: | 
+        run: |
           git clone --depth 1 https://github.com/cisco/ChezScheme
           c:\msys64\usr\bin\bash -l -c "pacman -S --noconfirm tar make"
           echo "::set-env name=PWD::$(c:\msys64\usr\bin\cygpath -u $(pwd))"
diff --git a/tests/Main.idr b/tests/Main.idr
index 206f241cb..c33ed4160 100644
--- a/tests/Main.idr
+++ b/tests/Main.idr
@@ -165,6 +165,8 @@ record Options where
   constructor MkOptions
   ||| Name of the idris2 executable
   idris2      : String
+  ||| Name of the codegenerator to use for `exec`
+  codegen     : Maybe String
   ||| Should we only run some specific cases?
   onlyNames   : List String
   ||| Should we run the test suite interactively?
@@ -175,7 +177,7 @@ usage = "Usage: runtests <idris2 path> [--interactive] [--only [NAMES]]"
 
 options : List String -> Maybe Options
 options args = case args of
-    (_ :: idris2 :: rest) => go rest (MkOptions idris2 [] False)
+    (_ :: idris2 :: rest) => go rest (MkOptions idris2 Nothing [] False)
     _ => Nothing
 
   where
@@ -184,6 +186,7 @@ options args = case args of
     go rest opts = case rest of
       []                      => pure opts
       ("--interactive" :: xs) => go xs (record { interactive = True } opts)
+      ("--cg" :: cg :: xs)    => go xs (record { codegen = Just cg } opts)
       ("--only" :: xs)        => pure $ record { onlyNames = xs } opts
       _ => Nothing
 
@@ -247,7 +250,10 @@ runTest opts testPath
         runTest' : IO Bool
         runTest'
             = do putStr $ testPath ++ ": "
-                 system $ "sh ./run " ++ idris2 opts ++ " | tr -d '\\r' > output"
+                 let cg = case codegen opts of
+                            Nothing => ""
+                            Just cg => "env IDRIS2_TESTS_CG=" ++ cg ++ " "
+                 system $ cg ++ "sh ./run " ++ idris2 opts ++ " | tr -d '\\r' > output"
                  Right out <- readFile "output"
                      | Left err => do print err
                                       pure False
@@ -299,6 +305,19 @@ findNode
     = do Just chez <- getEnv "NODE" | Nothing => pathLookup ["node"]
          pure $ Just chez
 
+findRacket : IO (Maybe String)
+findRacket
+  = do Just racket <- getEnv "RACKET" | Nothing => pathLookup ["racket"]
+       pure $ Just racket
+
+findCG : IO (Maybe String)
+findCG
+  = do Nothing <- getEnv "IDRIS2_CG" | p => pure p
+       Nothing <- findChez   | p => pure (Just "chez")
+       Nothing <- findNode   | p => pure (Just "node")
+       Nothing <- findRacket | p => pure (Just "racket")
+       pure Nothing
+
 runChezTests : Options -> List String -> IO (List Bool)
 runChezTests opts tests
     = do chexec <- findChez
@@ -329,6 +348,9 @@ main
          let (Just opts) = options args
               | _ => do print args
                         putStrLn usage
+         opts <- case codegen opts of
+                   Nothing => pure $ record { codegen = !findCG } opts
+                   Just _ => pure opts
          let filteredNonCGTests =
               filterTests opts $ concat $
                  [ testPaths "ttimp" ttimpTests