diff --git a/src/unix/bsd/freebsdlike/dragonfly/mod.rs b/src/unix/bsd/freebsdlike/dragonfly/mod.rs
index f399f27c..ad9959a1 100644
--- a/src/unix/bsd/freebsdlike/dragonfly/mod.rs
+++ b/src/unix/bsd/freebsdlike/dragonfly/mod.rs
@@ -1,3 +1,4 @@
+pub type c_char = i8;
 pub type clock_t = u64;
 pub type ino_t = u64;
 pub type lwpid_t = i32;
diff --git a/src/unix/bsd/freebsdlike/freebsd/aarch64.rs b/src/unix/bsd/freebsdlike/freebsd/aarch64.rs
index 3d61f889..7f4ed895 100644
--- a/src/unix/bsd/freebsdlike/freebsd/aarch64.rs
+++ b/src/unix/bsd/freebsdlike/freebsd/aarch64.rs
@@ -1,3 +1,4 @@
+pub type c_char = u8;
 pub type c_long = i64;
 pub type c_ulong = u64;
 pub type time_t = i64;
@@ -29,4 +30,5 @@ s! {
     }
 }
 
+pub const __MINSIGSTKSZ: ::size_t = 1024 * 4;
 pub const MAP_32BIT: ::c_int = 0x00080000;
diff --git a/src/unix/bsd/freebsdlike/freebsd/mod.rs b/src/unix/bsd/freebsdlike/freebsd/mod.rs
index a2a6d693..d7be64ea 100644
--- a/src/unix/bsd/freebsdlike/freebsd/mod.rs
+++ b/src/unix/bsd/freebsdlike/freebsd/mod.rs
@@ -161,10 +161,11 @@ s! {
 
 pub const SIGEV_THREAD_ID: ::c_int = 4;
 
+pub const MINSIGSTKSZ: ::size_t = __MINSIGSTKSZ;
 pub const RAND_MAX: ::c_int = 0x7fff_fffd;
-pub const PTHREAD_STACK_MIN: ::size_t = 2048;
+pub const PTHREAD_STACK_MIN: ::size_t = MINSIGSTKSZ;
 pub const PTHREAD_MUTEX_ADAPTIVE_NP: ::c_int = 4;
-pub const SIGSTKSZ: ::size_t = 34816;
+pub const SIGSTKSZ: ::size_t = MINSIGSTKSZ + 32768;
 pub const SF_NODISKIO: ::c_int = 0x00000001;
 pub const SF_MNOWAIT: ::c_int = 0x00000002;
 pub const SF_SYNC: ::c_int = 0x00000004;
diff --git a/src/unix/bsd/freebsdlike/freebsd/x86.rs b/src/unix/bsd/freebsdlike/freebsd/x86.rs
index 8a5e5f9f..ba98f91c 100644
--- a/src/unix/bsd/freebsdlike/freebsd/x86.rs
+++ b/src/unix/bsd/freebsdlike/freebsd/x86.rs
@@ -1,3 +1,4 @@
+pub type c_char = i8;
 pub type c_long = i32;
 pub type c_ulong = u32;
 pub type time_t = i32;
@@ -29,3 +30,5 @@ s! {
         __unused: [u8; 8],
     }
 }
+
+pub const __MINSIGSTKSZ: ::size_t = 512 * 4;
diff --git a/src/unix/bsd/freebsdlike/freebsd/x86_64.rs b/src/unix/bsd/freebsdlike/freebsd/x86_64.rs
index 3d61f889..106ad897 100644
--- a/src/unix/bsd/freebsdlike/freebsd/x86_64.rs
+++ b/src/unix/bsd/freebsdlike/freebsd/x86_64.rs
@@ -1,3 +1,4 @@
+pub type c_char = i8;
 pub type c_long = i64;
 pub type c_ulong = u64;
 pub type time_t = i64;
@@ -29,4 +30,5 @@ s! {
     }
 }
 
+pub const __MINSIGSTKSZ: ::size_t = 512 * 4;
 pub const MAP_32BIT: ::c_int = 0x00080000;
diff --git a/src/unix/bsd/freebsdlike/mod.rs b/src/unix/bsd/freebsdlike/mod.rs
index b3922426..76f42990 100644
--- a/src/unix/bsd/freebsdlike/mod.rs
+++ b/src/unix/bsd/freebsdlike/mod.rs
@@ -1,4 +1,3 @@
-pub type c_char = i8;
 pub type dev_t = u32;
 pub type mode_t = u16;
 pub type pthread_attr_t = *mut ::c_void;
@@ -84,7 +83,10 @@ s! {
 
     pub struct stack_t {
         // In FreeBSD 11 and later, ss_sp is actually a void*
+        #[cfg(not(target_arch = "aarch64"))]
         pub ss_sp: *mut ::c_char,
+        #[cfg(target_arch = "aarch64")]
+        pub ss_sp: *mut ::c_void,
         pub ss_size: ::size_t,
         pub ss_flags: ::c_int,
     }