diff --git a/zealbooter/GNUmakefile b/zealbooter/GNUmakefile
index 54eca6ed..6752229c 100644
--- a/zealbooter/GNUmakefile
+++ b/zealbooter/GNUmakefile
@@ -54,7 +54,6 @@ override CFLAGS += \
     -fno-PIC \
     -m64 \
     -march=x86-64 \
-    -mabi=sysv \
     -mno-80387 \
     -mno-mmx \
     -mno-sse \