diff --git a/src/solid/aarch64.rs b/src/solid/aarch64.rs
index ceabea397b804..4032488b6c0d5 100644
--- a/src/solid/aarch64.rs
+++ b/src/solid/aarch64.rs
@@ -1,4 +1,4 @@
-pub type c_char = i8;
+pub type c_char = u8;
 pub type wchar_t = u32;
 pub type c_long = i64;
 pub type c_ulong = u64;
diff --git a/src/solid/arm.rs b/src/solid/arm.rs
index 04cc1542deaeb..55240068aa08e 100644
--- a/src/solid/arm.rs
+++ b/src/solid/arm.rs
@@ -1,4 +1,4 @@
-pub type c_char = i8;
+pub type c_char = u8;
 pub type wchar_t = u32;
 pub type c_long = i32;
 pub type c_ulong = u32;