diff --git a/src/trap.zig b/src/trap.zig
index 1a63140..e88155f 100644
--- a/src/trap.zig
+++ b/src/trap.zig
@@ -79,8 +79,8 @@ pub const TrapCode = enum(u8) {
 pub const Trap = struct {
     /// Creates a new trap.
     /// The `Trap` returned is owned by the caller.
-    pub fn init(message: []const u8) Trap {
-        return wasmtime_trap_new(message.ptr, message.len);
+    pub fn init(message: [:0]const u8) Trap {
+        return wasmtime_trap_new(message.ptr, message.len + 1);
     }
 
     pub fn copy(self: *const Trap) Trap {