diff --git a/Makefile b/Makefile
index 74ea13c..a4c1e81 100644
--- a/Makefile
+++ b/Makefile
@@ -144,7 +144,7 @@ MANPAGES = ${MANPAGES_3}
 docs: ${MANPAGES}
 
 .c.o:
-	$(CC) -std=gnu99 -D_BSD_SOURCE -fPIC -DPIC ${CFLAGS} ${CPPFLAGS} -c -o $@ $<
+	$(CC) -std=gnu99 -D_DEFAULT_SOURCE -fPIC -DPIC ${CFLAGS} ${CPPFLAGS} -c -o $@ $<
 
 .S.o:
 	$(CC) -fPIC -DPIC ${CFLAGS} ${CPPFLAGS} ${ASFLAGS} -c -o $@ $<
@@ -233,7 +233,7 @@ check_libucontext_posix: test_libucontext_posix ${LIBUCONTEXT_POSIX_SONAME} ${LI
 	env LD_LIBRARY_PATH=$(shell pwd) ./test_libucontext_posix
 
 test_libucontext_posix: test_libucontext_posix.c ${LIBUCONTEXT_POSIX_NAME}
-	$(CC) -std=gnu99 -D_BSD_SOURCE ${CFLAGS} ${CPPFLAGS} $@.c -o $@ -L. -lucontext -lucontext_posix
+	$(CC) -std=gnu99 -D_DEFAULT_SOURCE ${CFLAGS} ${CPPFLAGS} $@.c -o $@ -L. -lucontext -lucontext_posix
 endif
 
 ifeq ($(EXPORT_UNPREFIXED),yes)
@@ -243,7 +243,7 @@ check_libucontext_bare_posixabi: test_libucontext_bare_posixabi ${LIBUCONTEXT_SO
 	env LD_LIBRARY_PATH=$(shell pwd) ./test_libucontext_bare_posixabi
 
 test_libucontext_bare_posixabi: test_libucontext_posix.c ${LIBUCONTEXT_NAME}
-	$(CC) -std=gnu99 -D_BSD_SOURCE ${CFLAGS} ${CPPFLAGS} test_libucontext_posix.c -o $@ -L. -lucontext
+	$(CC) -std=gnu99 -D_DEFAULT_SOURCE ${CFLAGS} ${CPPFLAGS} test_libucontext_posix.c -o $@ -L. -lucontext
 endif
 
 check_libucontext: test_libucontext ${LIBUCONTEXT_SONAME}
@@ -252,11 +252,11 @@ check_libucontext: test_libucontext ${LIBUCONTEXT_SONAME}
 check: check_libucontext
 
 test_libucontext: test_libucontext.c ${LIBUCONTEXT_NAME}
-	$(CC) -std=gnu99 -D_BSD_SOURCE ${CFLAGS} ${CPPFLAGS} $@.c -o $@ -L. -lucontext
+	$(CC) -std=gnu99 -D_DEFAULT_SOURCE ${CFLAGS} ${CPPFLAGS} $@.c -o $@ -L. -lucontext
 
 examples: ${LIBUCONTEXT_EXAMPLES}
 examples/cooperative_threading: examples/cooperative_threading.c ${LIBUCONTEXT_NAME}
-	$(CC) -std=gnu99 -D_BSD_SOURCE ${CFLAGS} ${CPPFLAGS} $@.c -o $@ -L. -lucontext
+	$(CC) -std=gnu99 -D_DEFAULT_SOURCE ${CFLAGS} ${CPPFLAGS} $@.c -o $@ -L. -lucontext
 
 ifeq ($(FREESTANDING),no)
 
diff --git a/arch/aarch64/include/libucontext/bits.h b/arch/aarch64/include/libucontext/bits.h
index e249448..5bcedc8 100644
--- a/arch/aarch64/include/libucontext/bits.h
+++ b/arch/aarch64/include/libucontext/bits.h
@@ -11,10 +11,10 @@ typedef struct {
 } libucontext_fpregset_t;
 
 typedef struct sigcontext {
-	unsigned long fault_address;
-	unsigned long regs[31];
-	unsigned long sp, pc, pstate;
-	long double __reserved[256];
+	unsigned long long fault_address;
+	unsigned long long regs[31];
+	unsigned long long sp, pc, pstate;
+	unsigned char __reserved[4096] __attribute__((aligned(16)));
 } libucontext_mcontext_t;
 
 typedef struct {
diff --git a/arch/aarch64/makecontext.c b/arch/aarch64/makecontext.c
index f6823cf..8f384cb 100644
--- a/arch/aarch64/makecontext.c
+++ b/arch/aarch64/makecontext.c
@@ -30,7 +30,7 @@ void
 libucontext_makecontext(libucontext_ucontext_t *ucp, void (*func)(void), int argc, ...)
 {
 	unsigned long *sp;
-	unsigned long *regp;
+	unsigned long long *regp;
 	va_list va;
 	int i;
 
@@ -48,7 +48,7 @@ libucontext_makecontext(libucontext_ucontext_t *ucp, void (*func)(void), int arg
 	regp = &(ucp->uc_mcontext.regs[0]);
 
 	for (i = 0; (i < argc && i < 8); i++)
-		*regp++ = va_arg (va, unsigned long);
+		*regp++ = va_arg (va, unsigned long long);
 
 	for (; i < argc; i++)
 		*sp++ = va_arg (va, unsigned long);