diff --git a/.gitlab/ci.sh b/.gitlab/ci.sh
index 751b09c7eac1de03187d7db85ea9f3982d334f84..75eaa3c289855d3e3ba05f4ec081b8ae6a537274 100755
--- a/.gitlab/ci.sh
+++ b/.gitlab/ci.sh
@@ -36,6 +36,7 @@ case "$(uname -s)" in
 		case "$(/usr/bin/arch)" in
 			aarch64|arm64|armv8l)
 				curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | arch -arm64 /bin/bash
+				export C_INCLUDE_PATH="`xcrun --show-sdk-path`/usr/include/ffi"
 				;;
 			*)
 				curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | sh