diff --git a/functions.sh.in b/functions.sh.in
index 82ac114..5fef9b0 100644
--- a/functions.sh.in
+++ b/functions.sh.in
@@ -117,21 +117,18 @@ readconfig() {
 	USE_COLORS=${_USE_COLORS-$USE_COLORS}
 	USE_CCACHE=${_USE_CCACHE-$USE_CCACHE}
 
-	[ -z "$CBUILD" ] && CBUILD="$(${CC:-gcc} -dumpmachine 2>/dev/null || true)"
+	[ -z "$CBUILD" ] && CBUILD="$(${APK:-apk} --print-arch 2>/dev/null)"
 	[ -z "$CHOST" ] && CHOST="$CBUILD"
 	[ -z "$CTARGET" ] && CTARGET="$CHOST"
 	[ "$(arch_to_hostspec $CBUILD)" != "unknown" ] && CBUILD="$(arch_to_hostspec $CBUILD)"
 	[ "$(arch_to_hostspec $CHOST)" != "unknown" ] && CHOST="$(arch_to_hostspec $CHOST)"
 	[ "$(arch_to_hostspec $CTARGET)" != "unknown" ] && CTARGET="$(arch_to_hostspec $CTARGET)"
-
-	[ -z "$CARCH" ] && CARCH="$(hostspec_to_arch $CHOST)"
-
-	# use apk --print-arch for CARCH if gcc is missing
-	if [ "$CARCH" = "unknown" ]; then
-		local apk_arch="$(${APK:-apk} --print-arch 2>/dev/null)"
-		CARCH=${apk_arch:-unknown}
+	if [ -z "$CBUILD" ]; then
+		echo "Unable to deduce build architecture. Install apk-tools, or set CBUILD."
+		exit 1
 	fi
 
+	[ -z "$CARCH" ] && CARCH="$(hostspec_to_arch $CHOST)"
 	[ -z "$CLIBC" ] && CLIBC="$(hostspec_to_libc $CHOST)"
 	[ -z "$CBUILD_ARCH" ] && CBUILD_ARCH="$(hostspec_to_arch $CBUILD)"
 	[ -z "$CTARGET_ARCH" ] && CTARGET_ARCH="$(hostspec_to_arch $CTARGET)"