diff --git a/packages/dart/build.sh b/packages/dart/build.sh
index f8d470c83..22d93c699 100644
--- a/packages/dart/build.sh
+++ b/packages/dart/build.sh
@@ -30,13 +30,13 @@ termux_step_get_source() {
 
 termux_step_post_get_source() {
 	if [ $TERMUX_ARCH = "arm" ]; then
-		export DEST_CPU="ARM"
+		export DEST_CPU="arm"
 	elif [ $TERMUX_ARCH = "i686" ]; then
-		export DEST_CPU="IA32"
+		export DEST_CPU="ia32"
 	elif [ $TERMUX_ARCH = "aarch64" ]; then
-		export DEST_CPU="ARM64"
+		export DEST_CPU="arm64"
 	elif [ $TERMUX_ARCH = "x86_64" ]; then
-		export DEST_CPU="X64"
+		export DEST_CPU="x64"
 	else
 		termux_error_exit "Unsupported arch '$TERMUX_ARCH'"
 	fi