diff --git a/capi/include/tendril.h b/capi/include/tendril.h
index 6e8a937..8ee0d70 100644
--- a/capi/include/tendril.h
+++ b/capi/include/tendril.h
@@ -102,7 +102,7 @@ void tendril_debug_dump(const tendril *t, FILE *stream);
 //// implementation details follow
 ////
 
-__attribute__((packed)) struct tendril_impl {
+struct tendril_impl {
     uintptr_t __ptr;
     uint32_t __a;
     uint32_t __b;
diff --git a/src/buf32.rs b/src/buf32.rs
index 9fe7316..3b1f911 100644
--- a/src/buf32.rs
+++ b/src/buf32.rs
@@ -16,7 +16,6 @@ pub const MAX_LEN: usize = u32::MAX as usize;
 
 /// A buffer points to a header of type `H`, which is followed by `MIN_CAP` or more
 /// bytes of storage.
-#[repr(packed)]
 pub struct Buf32<H> {
     pub ptr: *mut H,
     pub len: u32,
diff --git a/src/tendril.rs b/src/tendril.rs
index 171a1ed..eba2c2b 100644
--- a/src/tendril.rs
+++ b/src/tendril.rs
@@ -186,7 +186,7 @@ pub enum SubtendrilError {
 ///
 /// The maximum length of a `Tendril` is 4 GB. The library will panic if
 /// you attempt to go over the limit.
-#[repr(packed)]
+#[repr(C)]
 pub struct Tendril<F, A = NonAtomic>
     where F: fmt::Format,
           A: Atomicity,