--- a/ninja.SlackBuild	2021-02-10 20:58:44.692265458 +0200
+++ b/ninja.SlackBuild	2021-02-10 20:59:21.316235236 +0200
@@ -63,6 +63,14 @@
   SLKCFLAGS="-O3 -march=armv7-a -mfpu=vfpv3-d16"
   SLKLDFLAGS=""
   LIBDIRSUFFIX=""
+elif [ "$ARCH" = "aarch64" ]; then
+  SLKCFLAGS="-O2 -fPIC"
+  SLKLDFLAGS="-L/usr/lib64"
+  LIBDIRSUFFIX="64"
+elif [ "$ARCH" = "riscv64" ]; then
+  SLKCFLAGS="-O2 -fPIC"
+  SLKLDFLAGS="-L/usr/lib64"
+  LIBDIRSUFFIX="64"
 else
   SLKCFLAGS="-O2"
   SLKLDFLAGS=""