diff --git a/src/unix/mod.rs b/src/unix/mod.rs
index 59fd7254441f4..66ab0d5ca988a 100644
--- a/src/unix/mod.rs
+++ b/src/unix/mod.rs
@@ -14,6 +14,7 @@ pub type intptr_t = isize;
 pub type uintptr_t = usize;
 pub type ssize_t = isize;
 
+#[cfg(not(target_os = "nuttx"))]
 pub type pid_t = i32;
 pub type in_addr_t = u32;
 pub type in_port_t = u16;
diff --git a/src/unix/nuttx/mod.rs b/src/unix/nuttx/mod.rs
index 0f65225fe48f3..62b3cba42c7ef 100644
--- a/src/unix/nuttx/mod.rs
+++ b/src/unix/nuttx/mod.rs
@@ -6,6 +6,7 @@ use crate::{
     DIR,
 };
 
+pub type pid_t = c_int;
 pub type nlink_t = u16;
 pub type ino_t = u16;
 pub type blkcnt_t = u64;
@@ -24,13 +25,20 @@ pub type pthread_rwlockattr_t = i32;
 pub type pthread_t = i32;
 pub type rlim_t = i64;
 pub type sa_family_t = u16;
-pub type socklen_t = u32;
+pub type socklen_t = c_uint;
 pub type speed_t = usize;
 pub type suseconds_t = i32;
 pub type tcflag_t = u32;
-pub type clockid_t = i32;
+pub type clockid_t = c_int;
 pub type time_t = i64;
-pub type wchar_t = i32;
+
+cfg_if! {
+    if #[cfg(any(target_arch = "riscv32", target_arch = "riscv64"))] {
+        pub type wchar_t = c_int;
+    } else if #[cfg(any(target_arch = "arm", target_arch = "aarch64"))] {
+        pub type wchar_t = c_uint;
+    }
+}
 
 s! {
     pub struct stat {