diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2e437f1..9d76d14 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -158,4 +158,4 @@ jobs:
           nim --version
           nimble --version
           nimble install -y --depsOnly
-          env TEST_LANG="c" nimble test
+          env NIMLANG="c" nimble test
diff --git a/.gitignore b/.gitignore
index fa19c26..0e5fc52 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,7 @@
 nimcache/
 *.exe
-gen
 nimble.develop
 nimble.paths
+/build/
+
+gen
diff --git a/bearssl.nimble b/bearssl.nimble
index 39186e8..31cd779 100644
--- a/bearssl.nimble
+++ b/bearssl.nimble
@@ -1,27 +1,41 @@
-import os, strutils
+mode = ScriptMode.Verbose
 
-# Package
+packageName   = "bearssl"
 version       = "0.1.5"
 author        = "Status Research & Development GmbH"
 description   = "BearSSL wrapper"
 license       = "MIT or Apache License 2.0"
-mode          = ScriptMode.Verbose
+skipDirs      = @["tests"]
 
-# Dependencies
 requires "nim >= 1.2.0",
-          "unittest2"
+         "unittest2"
 
-### Helper functions
-proc test(env, path: string) =
-  # Compilation language is controlled by TEST_LANG
-  exec "nim " & getEnv("TEST_LANG", "c") & " " & getEnv("NIMFLAGS") & " " & env &
-    " -d:bearsslSplitAbi -rf --hints:off --skipParentCfg --styleCheck:usages --styleCheck:error " & path
+let nimc = getEnv("NIMC", "nim") # Which nim compiler to use
+let lang = getEnv("NIMLANG", "c") # Which backend (c/cpp/js)
+let flags = getEnv("NIMFLAGS", "") # Extra flags for the compiler
+let verbose = getEnv("V", "") notin ["", "0"]
+
+let styleCheckStyle = if (NimMajor, NimMinor) < (1, 6): "hint" else: "error"
+let cfg =
+  " --styleCheck:usages --styleCheck:" & styleCheckStyle &
+  (if verbose: "" else: " --verbosity:0 --hints:off") &
+  " --skipParentCfg --skipUserCfg --outdir:build --nimcache:build/nimcache -f"
+
+proc build(args, path: string) =
+  exec nimc & " " & lang & " " & cfg & " " & flags & " " & args & " " & path
+
+proc run(args, path: string) =
+  build args & " -r", path
+
+import strutils
 
 task test, "Run tests":
-  for path in listFiles(thisDir() / "tests"):
-    if path.split(".")[^1] != "nim":
-      continue
-    test "-d:debug", path
-    test "-d:release", path
-    test "--gc:arc -d:release", path
-    rmFile(path[0..^5].toExe())
+  for path in listFiles("tests"):
+    if not path.endsWith ".nim": continue
+
+    for args in [
+      "-d:debug",
+      "-d:release",
+      "-d:bearsslSplitAbi -d:debug",
+      "-d:bearsslSplitAbi -d:release",
+    ]: run args, path
diff --git a/bearssl/abi/bearssl_ssl.nim b/bearssl/abi/bearssl_ssl.nim
index 4bb57b3..547a829 100644
--- a/bearssl/abi/bearssl_ssl.nim
+++ b/bearssl/abi/bearssl_ssl.nim
@@ -1132,11 +1132,11 @@ type
     hashCV_len* {.importc: "hash_CV_len".}: uint
     hashCV_id* {.importc: "hash_CV_id".}: cint
 
-proc sslSessionCacheLruInit*(cc: var SslSessionCacheLru; store: ptr cuchar;
+proc sslSessionCacheLruInit*(cc: var SslSessionCacheLru; store: ptr byte;
                             storeLen: int) {.importcFunc,
     importc: "br_ssl_session_cache_lru_init", header: "bearssl_ssl.h".}
 
-proc sslSessionCacheLruForget*(cc: var SslSessionCacheLru; id: ptr cuchar) {.importcFunc,
+proc sslSessionCacheLruForget*(cc: var SslSessionCacheLru; id: ptr byte) {.importcFunc,
     importc: "br_ssl_session_cache_lru_forget", header: "bearssl_ssl.h".}
 
 
diff --git a/regenerate.sh b/regenerate.sh
old mode 100644
new mode 100755