diff --git a/Makefile b/Makefile
index dd222a8..080c748 100644
--- a/Makefile
+++ b/Makefile
@@ -101,7 +101,7 @@ ifeq ($(shell :|$(CC) -fstack-protector-strong -S -xc - -o - >/dev/null 2>&1; ec
 	FLAGS += -fstack-protector-strong
 endif
 
-C := \#define _GNU_SOURCE\n\#include <fcntl.h>\nx = FALLOC_FL_COLLAPSE_RANGE;
+C := \#define _GNU_SOURCE\n\#include <fcntl.h>\nint x = FALLOC_FL_COLLAPSE_RANGE;
 ifeq ($(shell printf "$(C)" | $(CC) -S -xc - -o - >/dev/null 2>&1; echo $$?),0)
 	EXTRA_SYSCALLS += fallocate
 endif