diff --git a/releasenotes.md b/releasenotes.md
index 594681cd4..306486dfd 100644
--- a/releasenotes.md
+++ b/releasenotes.md
@@ -15,6 +15,8 @@
 - `--no-headers` option to suppress creating headers when generating a library.
 - Support c-file compilation in libraries.
 - Allow using $defined(&a[1]) to check if the operation is supported.
+- Max number of members in a struct is limited to 65535.
+- The maximum number of parameters in a call is now 255, up from 127.
 
 ### Fixes
 - Error with unsigned compare in `@ensure` when early returning 0 #1207.
@@ -35,6 +37,7 @@
 - Fix ABI lowering for 128 bit vectors on Linux.
 - Bad error message when using a generic method without generic parameters #1228
 - Private function called from nested macro not visible to linker #1232
+- Bitstructs in structs would not be correctly be handled in some cases.
 
 ### Stdlib changes
 - Added `remove_first_item` `remove_last_item` and `remove_item` as aliases for the `match` functions.
diff --git a/src/compiler/copying.c b/src/compiler/copying.c
index a504bc039..5673bbd0e 100644
--- a/src/compiler/copying.c
+++ b/src/compiler/copying.c
@@ -907,6 +907,7 @@ Decl *copy_decl(CopyStruct *c, Decl *decl)
 			copy_decl_type(copy);
 			MACRO_COPY_TYPE_LIST(copy->interfaces);
 			MACRO_COPY_DECL_LIST(copy->strukt.members);
+			MACRO_COPY_DECLID(copy->strukt.padded_decl_id);
 			MACRO_COPY_DECL_LIST(copy->methods);
 			break;
 		case DECL_DECLARRAY:
diff --git a/src/compiler/llvm_codegen.c b/src/compiler/llvm_codegen.c
index 291dc5d88..e28ae88d0 100644
--- a/src/compiler/llvm_codegen.c
+++ b/src/compiler/llvm_codegen.c
@@ -271,8 +271,7 @@ LLVMValueRef llvm_emit_const_initializer(GenContext *c, ConstInitializer *const_
 			LLVMTypeRef element_type_llvm = llvm_get_type(c, element_type);
 			AlignSize expected_align = llvm_abi_alignment(c, element_type_llvm);
 			ConstInitializer **elements = const_init->init_array.elements;
-			unsigned element_count = vec_size(elements);
-			assert(element_count > 0 && "Array should always have gotten at least one element.");
+			assert(vec_size(elements) > 0 && "Array should always have gotten at least one element.");
 			ArrayIndex current_index = 0;
 			unsigned alignment = 0;
 			LLVMValueRef *parts = NULL;
diff --git a/src/compiler/llvm_codegen_expr.c b/src/compiler/llvm_codegen_expr.c
index 6b3f9c660..ecdc217f9 100644
--- a/src/compiler/llvm_codegen_expr.c
+++ b/src/compiler/llvm_codegen_expr.c
@@ -804,14 +804,16 @@ static void llvm_emit_member_addr(GenContext *c, BEValue *value, Decl *parent, D
 	} while (found != member);
 }
 
-static void llvm_emit_bitstruct_member(GenContext *c, BEValue *value, Decl *parent, Decl *member)
+static Decl *llvm_emit_bitstruct_member(GenContext *c, BEValue *value, Decl *parent, Decl *member)
 {
 	assert(member->resolve_status == RESOLVE_DONE);
-	Decl *found = NULL;
+	Decl *found = parent;
+	Decl *last = NULL;
 	do
 	{
 		ArrayIndex index = find_member_index(parent, member);
 		assert(index > -1);
+		last = found;
 		found = parent->strukt.members[index];
 		switch (parent->type->canonical->type_kind)
 		{
@@ -829,6 +831,7 @@ static void llvm_emit_bitstruct_member(GenContext *c, BEValue *value, Decl *pare
 		}
 		parent = found;
 	} while (found != member);
+	return last ? last : parent;
 }
 
 static LLVMValueRef llvm_emit_bswap(GenContext *c, LLVMValueRef value)
@@ -838,6 +841,7 @@ static LLVMValueRef llvm_emit_bswap(GenContext *c, LLVMValueRef value)
 		return LLVMConstBswap(value);
 	}
 	LLVMTypeRef type = LLVMTypeOf(value);
+	assert(type != c->byte_type);
 	return llvm_emit_call_intrinsic(c, intrinsic_id.bswap, &type, 1, &value, 1);
 }
 
@@ -871,6 +875,7 @@ static inline void llvm_extract_bool_bit_from_array(GenContext *c, BEValue *be_v
 static inline LLVMValueRef llvm_bswap_non_integral(GenContext *c, LLVMValueRef value, unsigned bitsize)
 {
 	if (bitsize <= 8) return value;
+	assert(is_power_of_two(bitsize));
 	LLVMValueRef shifted = llvm_emit_shl_fixed(c, value, (int)llvm_bitsize(c, LLVMTypeOf(value)) - (int)bitsize);
 	return llvm_emit_bswap(c, shifted);
 }
@@ -942,9 +947,8 @@ static inline void llvm_extract_bitvalue_from_array(GenContext *c, BEValue *be_v
 }
 
 
-static inline void llvm_extract_bitvalue(GenContext *c, BEValue *be_value, Expr *parent, Decl *member)
+static inline void llvm_extract_bitvalue(GenContext *c, BEValue *be_value, Decl *parent_decl, Decl *member)
 {
-	Decl *parent_decl = type_flatten(parent->type)->decl;
 	if (be_value->type->type_kind == TYPE_ARRAY)
 	{
 		llvm_extract_bitvalue_from_array(c, be_value, member, parent_decl);
@@ -1126,14 +1130,14 @@ static inline void llvm_emit_bitassign_expr(GenContext *c, BEValue *be_value, Ex
 	BEValue parent;
 	Decl *member = lhs->access_expr.ref;
 	llvm_emit_expr(c, &parent, parent_expr);
-	llvm_emit_bitstruct_member(c, &parent, type_flatten(parent_expr->type)->decl, member);
+	Decl *parent_decl = llvm_emit_bitstruct_member(c, &parent, type_flatten(parent_expr->type)->decl, member);
 
 	// If we have assign + op, load the current value, perform the operation.
 	if (expr->binary_expr.operator != BINARYOP_ASSIGN)
 	{
 		// Grab the current value.
 		BEValue value = parent;
-		llvm_extract_bitvalue(c, &value, parent_expr, member);
+		llvm_extract_bitvalue(c, &value, parent_decl, member);
 		// Perform the operation and place it in be_value
 		llvm_emit_binary(c, be_value, expr, &value, binaryop_assign_base_op(expr->binary_expr.operator));
 	}
@@ -1152,10 +1156,10 @@ static inline void llvm_emit_bitassign_expr(GenContext *c, BEValue *be_value, Ex
 
 	// To start the assign, pull out the current value.
 	LLVMValueRef current_value = llvm_load_value_store(c, &parent);
-	bool bswap = bitstruct_requires_bitswap(parent_type->decl);
+	bool bswap = bitstruct_requires_bitswap(parent_decl);
 	if (bswap) current_value = llvm_emit_bswap(c, current_value);
 	LLVMValueRef value = llvm_load_value_store(c, be_value);
-	current_value = llvm_emit_bitstruct_value_update(c, current_value, type_size(parent.type) * 8, LLVMTypeOf(current_value), member, value);
+	current_value = llvm_emit_bitstruct_value_update(c, current_value, type_size(parent_decl->type) * 8, LLVMTypeOf(current_value), member, value);
 	if (bswap) current_value = llvm_emit_bswap(c, current_value);
 	llvm_store_raw(c, &parent, current_value);
 }
@@ -1167,8 +1171,8 @@ static inline void llvm_emit_bitaccess(GenContext *c, BEValue *be_value, Expr *e
 	Decl *member = expr->access_expr.ref;
 	assert(be_value && be_value->type);
 
-	llvm_emit_bitstruct_member(c, be_value, type_flatten(parent->type)->decl, member);
-	llvm_extract_bitvalue(c, be_value, parent, expr->access_expr.ref);
+	Decl *parent_decl = llvm_emit_bitstruct_member(c, be_value, type_flatten(parent->type)->decl, member);
+	llvm_extract_bitvalue(c, be_value, parent_decl, expr->access_expr.ref);
 }
 
 static inline void llvm_emit_access_addr(GenContext *c, BEValue *be_value, Expr *expr)
@@ -2037,7 +2041,7 @@ static void llvm_emit_initialize_designated_element(GenContext *c, BEValue *ref,
 				llvm_emit_expr(c, &exprval, expr);
 				LLVMValueRef val = llvm_load_value_store(c, &exprval);
 				LLVMTypeRef bitstruct_type = llvm_get_type(c, underlying_type);
-				bool is_bitswap = bitstruct_requires_bitswap(decl);
+				bool is_bitswap = bitstruct_requires_bitswap(type->decl);
 				if (underlying_type->type_kind == TYPE_ARRAY)
 				{
 					llvm_emit_update_bitstruct_array(c, value.value, value.alignment, bitstruct_type, is_bitswap, member, val);
@@ -2150,6 +2154,7 @@ static inline void llvm_emit_initialize_reference_designated(GenContext *c, BEVa
 
 static bool bitstruct_requires_bitswap(Decl *decl)
 {
+	assert(decl->decl_kind == DECL_BITSTRUCT);
 	bool big_endian = platform_target.big_endian;
 	if (decl->bitstruct.big_endian) return !big_endian;
 	if (decl->bitstruct.little_endian) return big_endian;
@@ -2435,27 +2440,26 @@ static inline void llvm_emit_pre_post_inc_dec_bitstruct(GenContext *c, BEValue *
 	BEValue parent;
 	Decl *member = lhs->access_expr.ref;
 	llvm_emit_expr(c, &parent, parent_expr);
-	llvm_emit_bitstruct_member(c, &parent, type_flatten(parent_expr->type)->decl, member);
+	Decl *parent_decl = llvm_emit_bitstruct_member(c, &parent, type_flatten(parent_expr->type)->decl, member);
 
 	BEValue value = parent;
-	llvm_extract_bitvalue(c, &value, parent_expr, member);
+	llvm_extract_bitvalue(c, &value, parent_decl, member);
 	LLVMValueRef value_start = llvm_load_value_store(c, &value);
 	LLVMValueRef result = llvm_emit_add_int(c, value.type, value_start, llvm_const_int(c, value.type, diff), lhs->span);
 
 	llvm_value_set(be_value, pre ? result : value_start, value.type);
 
-	Type *parent_type = type_flatten(parent_expr->type);
-	if (type_lowering(parent_type)->type_kind == TYPE_ARRAY)
+	if (type_lowering(parent_decl->type)->type_kind == TYPE_ARRAY)
 	{
-		llvm_emit_bitassign_array(c, result, parent, parent_type->decl, member);
+		llvm_emit_bitassign_array(c, result, parent, parent_decl, member);
 		return;
 	}
 
 	// To start the assign, pull out the current value.
 	LLVMValueRef current_value = llvm_load_value_store(c, &parent);
-	bool bswap = bitstruct_requires_bitswap(parent_type->decl);
+	bool bswap = bitstruct_requires_bitswap(parent_decl);
 	if (bswap) current_value = llvm_emit_bswap(c, current_value);
-	current_value = llvm_emit_bitstruct_value_update(c, current_value, type_size(parent.type) * 8, LLVMTypeOf(current_value), member, result);
+	current_value = llvm_emit_bitstruct_value_update(c, current_value, type_size(parent_decl->type) * 8, LLVMTypeOf(current_value), member, result);
 	if (bswap) current_value = llvm_emit_bswap(c, current_value);
 	llvm_store_raw(c, &parent, current_value);
 }
diff --git a/src/compiler/sema_decls.c b/src/compiler/sema_decls.c
index 876e6e619..3bcfa12e7 100644
--- a/src/compiler/sema_decls.c
+++ b/src/compiler/sema_decls.c
@@ -276,7 +276,8 @@ static inline bool sema_analyse_struct_member(SemaContext *context, Decl *parent
 static inline bool sema_check_struct_holes(SemaContext *context, Decl *decl, Decl *member, Type *member_type) 
 {
 	member_type = type_flatten(member_type);
-	if (member_type->type_kind != TYPE_STRUCT && member_type->type_kind != TYPE_UNION) return true;
+	if (!type_is_union_or_strukt(member_type)) return true;
+	assert(decl_is_struct_type(member_type->decl));
 	if (!member_type->decl->strukt.padded_decl_id) return true;
 	if (!decl->strukt.padded_decl_id) decl->strukt.padded_decl_id = member_type->decl->strukt.padded_decl_id;
 	if (decl->attr_compact)
@@ -377,6 +378,7 @@ static bool sema_analyse_union_members(SemaContext *context, Decl *decl)
 	decl->is_packed = decl->is_packed && max_alignment > 1;
 
 	// "Representative" type is the one with the maximum alignment.
+	assert(max_alignment_element >= 0);
 	decl->strukt.union_rep = max_alignment_element;
 
 	// All members share the same alignment
@@ -590,6 +592,7 @@ static bool sema_analyse_struct_members(SemaContext *context, Decl *decl)
 
 		if (align_offset - offset != 0)
 		{
+			assert(decl_is_struct_type(decl));
 			if (!decl->strukt.padded_decl_id) decl->strukt.padded_decl_id = declid(member);
 			if (decl->attr_nopadding || member->attr_nopadding)
 			{
@@ -647,6 +650,7 @@ static bool sema_analyse_struct_members(SemaContext *context, Decl *decl)
 
 	if (size != offset)
 	{
+		assert(decl_is_struct_type(decl));
 		if (!decl->strukt.padded_decl_id) decl->strukt.padded_decl_id = declid(decl);
 		if (decl->attr_nopadding)
 		{
diff --git a/src/compiler/types.c b/src/compiler/types.c
index e81ffb78f..09e83324b 100644
--- a/src/compiler/types.c
+++ b/src/compiler/types.c
@@ -1013,7 +1013,7 @@ static inline bool array_structurally_equivalent_to_struct(Type *array, Type *ty
 	Decl **members = type->decl->strukt.members;
 
 	// For structs / errors, all members must match.
-	ArrayIndex  offset = 0;
+	ArrayIndex offset = 0;
 	AlignSize align_size = type_abi_alignment(array);
 	Type *array_base = array->array.base;
 	FOREACH(Decl *, member, members)
diff --git a/test/test_suite/functions/too_many_params.c3 b/test/test_suite/functions/too_many_params.c3
index c0a6917cf..5b7a190ca 100644
--- a/test/test_suite/functions/too_many_params.c3
+++ b/test/test_suite/functions/too_many_params.c3
@@ -7,11 +7,16 @@ fn int test1(
 	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, //
 	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, //
 	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, // 100
-	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, //
-	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, // #error:  The number of params exceeded the max of 127. To accept more arguments, consider using varargs
+	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, // 120
 	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, //
 	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, //
-	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int // 200
+	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, //
+	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, // 200
+	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, // 220
+	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, // 240
+	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, // #error:  The number of params exceeded
+	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, //
+	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int // 300
 ) { return 1; }
 
 fn int test2(
@@ -20,11 +25,16 @@ fn int test2(
 	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, //
 	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, //
 	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, // 100
+	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, // 120
 	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, //
-	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, // #error: The number of params exceeded the max of 127.
 	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, //
 	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, //
 	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, // 200
+	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, // 220
+	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, // 240
+	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, // #error:  The number of params exceeded
+	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, //
+	int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, // 300
 	int... x
 ) { return 1; }