diff --git a/src/all_types.hpp b/src/all_types.hpp
index 6ee3a6b937..c9bdfabb0d 100644
--- a/src/all_types.hpp
+++ b/src/all_types.hpp
@@ -3670,8 +3670,8 @@ static const size_t coro_fn_ptr_index = 1;
 static const size_t coro_awaiter_index = 2;
 static const size_t coro_arg_start = 3;
 
-// one for the GetSize block, one for the Entry block, resume blocks are indexed after that.
-static const size_t coro_extra_resume_block_count = 2;
+// one for the Entry block, resume blocks are indexed after that.
+static const size_t coro_extra_resume_block_count = 1;
 
 // TODO call graph analysis to find out what this number needs to be for every function
 // MUST BE A POWER OF TWO.
diff --git a/src/analyze.cpp b/src/analyze.cpp
index c8e02a4771..e1fedab7cf 100644
--- a/src/analyze.cpp
+++ b/src/analyze.cpp
@@ -7254,7 +7254,7 @@ static void resolve_llvm_types_fn_type(CodeGen *g, ZigType *fn_type) {
     ZigList<ZigLLVMDIType *> param_di_types = {};
     ZigType *gen_return_type;
     if (is_async) {
-        gen_return_type = g->builtin_types.entry_usize;
+        gen_return_type = g->builtin_types.entry_void;
         param_di_types.append(get_llvm_di_type(g, gen_return_type));
     } else if (!type_has_bits(fn_type_id->return_type)) {
         gen_return_type = g->builtin_types.entry_void;
@@ -7354,7 +7354,7 @@ void resolve_llvm_types_fn(CodeGen *g, ZigFn *fn) {
         return;
     }
 
-    ZigType *gen_return_type = g->builtin_types.entry_usize;
+    ZigType *gen_return_type = g->builtin_types.entry_void;
     ZigList<ZigLLVMDIType *> param_di_types = {};
     // first "parameter" is return value
     param_di_types.append(get_llvm_di_type(g, gen_return_type));
diff --git a/src/codegen.cpp b/src/codegen.cpp
index 4343006b17..63018cb6a3 100644
--- a/src/codegen.cpp
+++ b/src/codegen.cpp
@@ -1995,7 +1995,7 @@ static LLVMValueRef ir_render_return(CodeGen *g, IrExecutable *executable, IrIns
             LLVMBuildStore(g->builder, new_resume_index, resume_index_ptr);
         }
 
-        LLVMBuildRet(g->builder, LLVMGetUndef(g->builtin_types.entry_usize->llvm_type));
+        LLVMBuildRetVoid(g->builder);
         return nullptr;
     }
     if (want_first_arg_sret(g, &g->cur_fn->type_entry->data.fn.fn_type_id)) {
@@ -3438,7 +3438,7 @@ static LLVMValueRef ir_render_call(CodeGen *g, IrExecutable *executable, IrInstr
 
         LLVMValueRef call_inst = ZigLLVMBuildCall(g->builder, fn_val, &frame_result_loc, 1, llvm_cc, fn_inline, "");
         ZigLLVMSetTailCall(call_inst);
-        LLVMBuildRet(g->builder, call_inst);
+        LLVMBuildRetVoid(g->builder);
 
         LLVMPositionBuilderAtEnd(g->builder, instruction->resume_block->llvm_block);
         return nullptr;
@@ -4898,7 +4898,7 @@ static LLVMValueRef ir_render_suspend_begin(CodeGen *g, IrExecutable *executable
 static LLVMValueRef ir_render_suspend_br(CodeGen *g, IrExecutable *executable,
         IrInstructionSuspendBr *instruction)
 {
-    LLVMBuildRet(g->builder, LLVMGetUndef(g->builtin_types.entry_usize->llvm_type));
+    LLVMBuildRetVoid(g->builder);
     return nullptr;
 }
 
@@ -6426,27 +6426,17 @@ static void do_code_gen(CodeGen *g) {
             LLVMPositionBuilderAtEnd(g->builder, bad_resume_block);
             gen_assertion_scope(g, PanicMsgIdBadResume, fn_table_entry->child_scope);
 
-            LLVMBasicBlockRef get_size_block = LLVMAppendBasicBlock(g->cur_fn_val, "GetSize");
-            LLVMPositionBuilderAtEnd(g->builder, get_size_block);
-            assert(fn_table_entry->frame_type->abi_size != 0);
-            assert(fn_table_entry->frame_type->abi_size != SIZE_MAX);
-            LLVMBuildRet(g->builder, size_val);
-
             LLVMPositionBuilderAtEnd(g->builder, fn_table_entry->preamble_llvm_block);
             LLVMValueRef resume_index_ptr = LLVMBuildStructGEP(g->builder, g->cur_ret_ptr,
                     coro_resume_index_index, "");
             LLVMValueRef resume_index = LLVMBuildLoad(g->builder, resume_index_ptr, "");
             // +1 - index 0 is reserved for the entry block
-            // +1 - index 1 is reserved for getting the size.
             LLVMValueRef switch_instr = LLVMBuildSwitch(g->builder, resume_index, bad_resume_block,
-                    fn_table_entry->resume_blocks.length + 2);
+                    fn_table_entry->resume_blocks.length + 1);
 
             LLVMValueRef zero = LLVMConstNull(usize_type_ref);
             LLVMAddCase(switch_instr, zero, executable->basic_block_list.at(0)->llvm_block);
 
-            LLVMValueRef one = LLVMConstInt(usize_type_ref, 1, false);
-            LLVMAddCase(switch_instr, one, get_size_block);
-
             for (size_t resume_i = 0; resume_i < fn_table_entry->resume_blocks.length; resume_i += 1) {
                 IrBasicBlock *resume_block = fn_table_entry->resume_blocks.at(resume_i);
                 LLVMValueRef case_value = LLVMConstInt(usize_type_ref, resume_block->resume_index, false);