diff --git a/base/inference.jl b/base/inference.jl
index 92adaa78ede53..093908ebec6b2 100644
--- a/base/inference.jl
+++ b/base/inference.jl
@@ -289,7 +289,7 @@ function InferenceState(linfo::MethodInstance,
     # prepare an InferenceState object for inferring lambda
     # create copies of the CodeInfo definition, and any fields that type-inference might modify
     m = linfo.def::Method
-    if m.isstaged
+    if isdefined(m, :generator)
         try
             # user code might throw errors – ignore them
             src = get_staged(linfo)
@@ -1996,7 +1996,7 @@ function pure_eval_call(f::ANY, argtypes::ANY, atype::ANY, sv::InferenceState)
     meth = meth[1]::SimpleVector
     method = meth[3]::Method
     # TODO: check pure on the inferred thunk
-    if method.isstaged || !method.pure
+    if isdefined(method, :generator) || !method.pure
         return false
     end
 
@@ -2790,7 +2790,7 @@ function code_for_method(method::Method, atypes::ANY, sparams::SimpleVector, wor
     if world < min_world(method)
         return nothing
     end
-    if method.isstaged && !isleaftype(atypes)
+    if isdefined(method, :generator) && !isleaftype(atypes)
         # don't call staged functions on abstract types.
         # (see issues #8504, #10230)
         # we can't guarantee that their type behavior is monotonic.
@@ -4208,7 +4208,7 @@ function inlineable(f::ANY, ft::ANY, e::Expr, atypes::Vector{Any}, sv::Inference
     end
 
     # check whether call can be inlined to just a quoted constant value
-    if isa(f, widenconst(ft)) && !method.isstaged
+    if isa(f, widenconst(ft)) && !isdefined(method, :generator)
         if f === return_type
             if isconstType(e.typ)
                 return inline_as_constant(e.typ.parameters[1], argexprs, sv, invoke_data)
@@ -4250,7 +4250,7 @@ function inlineable(f::ANY, ft::ANY, e::Expr, atypes::Vector{Any}, sv::Inference
     # some gf have special tfunc, meaning they wouldn't have been inferred yet
     # check the same conditions from abstract_call to detect this case
     force_infer = false
-    if !method.isstaged
+    if !isdefined(method, :generator)
         if method.module == _topmod(method.module) || (isdefined(Main, :Base) && method.module == Main.Base)
             la = length(atypes)
             if (la==3 && (method.name == :getindex || method.name == :next)) ||
diff --git a/base/reflection.jl b/base/reflection.jl
index 8f0ae46e9d80b..bbf8b130d6a4e 100644
--- a/base/reflection.jl
+++ b/base/reflection.jl
@@ -682,7 +682,7 @@ function length(mt::MethodTable)
 end
 isempty(mt::MethodTable) = (mt.defs === nothing)
 
-uncompressed_ast(m::Method) = uncompressed_ast(m, m.source)
+uncompressed_ast(m::Method) = uncompressed_ast(m, isdefined(m,:source) ? m.source : m.generator.inferred)
 uncompressed_ast(m::Method, s::CodeInfo) = s
 uncompressed_ast(m::Method, s::Array{UInt8,1}) = ccall(:jl_uncompress_ast, Any, (Any, Any), m, s)::CodeInfo
 
@@ -799,7 +799,7 @@ code_native(::IO, ::ANY, ::Symbol) = error("illegal code_native call") # resolve
 
 # give a decent error message if we try to instantiate a staged function on non-leaf types
 function func_for_method_checked(m::Method, types::ANY)
-    if m.isstaged && !isleaftype(types)
+    if isdefined(m,:generator) && !isdefined(m,:source) && !isleaftype(types)
         error("cannot call @generated function `", m, "` ",
               "with abstract argument types: ", types)
     end
diff --git a/base/serialize.jl b/base/serialize.jl
index 17b19850b38fd..d6a5a73bd043e 100644
--- a/base/serialize.jl
+++ b/base/serialize.jl
@@ -398,8 +398,16 @@ function serialize(s::AbstractSerializer, meth::Method)
     serialize(s, meth.ambig)
     serialize(s, meth.nargs)
     serialize(s, meth.isva)
-    serialize(s, meth.isstaged)
-    serialize(s, uncompressed_ast(meth, meth.source))
+    if isdefined(meth, :source)
+        serialize(s, uncompressed_ast(meth, meth.source))
+    else
+        serialize(s, nothing)
+    end
+    if isdefined(meth, :generator)
+        serialize(s, uncompressed_ast(meth, meth.generator.inferred))
+    else
+        serialize(s, nothing)
+    end
     nothing
 end
 
@@ -783,8 +791,8 @@ function deserialize(s::AbstractSerializer, ::Type{Method})
     ambig = deserialize(s)::Union{Array{Any,1}, Void}
     nargs = deserialize(s)::Int32
     isva = deserialize(s)::Bool
-    isstaged = deserialize(s)::Bool
-    template = deserialize(s)::CodeInfo
+    template = deserialize(s)
+    generator = deserialize(s)
     if makenew
         meth.module = mod
         meth.name = name
@@ -793,16 +801,17 @@ function deserialize(s::AbstractSerializer, ::Type{Method})
         meth.sig = sig
         meth.sparam_syms = sparam_syms
         meth.ambig = ambig
-        meth.isstaged = isstaged
         meth.nargs = nargs
         meth.isva = isva
         # TODO: compress template
-        meth.source = template
-        meth.pure = template.pure
-        if isstaged
+        if template !== nothing
+            meth.source = template
+            meth.pure = template.pure
+        end
+        if generator !== nothing
             linfo = ccall(:jl_new_method_instance_uninit, Ref{Core.MethodInstance}, ())
             linfo.specTypes = Tuple
-            linfo.inferred = template
+            linfo.inferred = generator
             linfo.def = meth
             meth.generator = linfo
         end
diff --git a/base/show.jl b/base/show.jl
index 0209cc92c9fad..fe4ad307a1ab4 100644
--- a/base/show.jl
+++ b/base/show.jl
@@ -320,7 +320,7 @@ end
 function show(io::IO, l::Core.MethodInstance)
     def = l.def
     if isa(def, Method)
-        if def.isstaged && l === def.generator
+        if isdefined(def, :generator) && l === def.generator
             print(io, "MethodInstance generator for ")
             show(io, def)
         else
diff --git a/src/codegen.cpp b/src/codegen.cpp
index e8cd2c42a6660..a800306b9a741 100644
--- a/src/codegen.cpp
+++ b/src/codegen.cpp
@@ -1301,7 +1301,7 @@ static jl_method_instance_t *jl_get_unspecialized(jl_method_instance_t *method)
 {
     // one unspecialized version of a function can be shared among all cached specializations
     jl_method_t *def = method->def.method;
-    if (def->isstaged) {
+    if (def->source == NULL) {
         return method;
     }
     if (def->unspecialized == NULL) {
@@ -1340,7 +1340,7 @@ jl_generic_fptr_t jl_generate_fptr(jl_method_instance_t *li, void *_F, size_t wo
     }
     jl_method_instance_t *unspec = NULL;
     if (jl_is_method(li->def.method)) {
-        if (!li->def.method->isstaged && li->def.method->unspecialized) {
+        if (li->def.method->unspecialized) {
             unspec = li->def.method->unspecialized;
         }
         if (!F || !jl_can_finalize_function(F)) {
@@ -1349,7 +1349,11 @@ jl_generic_fptr_t jl_generate_fptr(jl_method_instance_t *li, void *_F, size_t wo
             // and return its fptr instead
             if (!unspec)
                 unspec = jl_get_unspecialized(li); // get-or-create the unspecialized version to cache the result
-            jl_code_info_t *src = unspec->def.method->isstaged ? jl_code_for_staged(unspec) : (jl_code_info_t*)unspec->def.method->source;
+            jl_code_info_t *src = (jl_code_info_t*)unspec->def.method->source;
+            if (src == NULL) {
+                assert(unspec->def.method->generator);
+                src = jl_code_for_staged(unspec);
+            }
             fptr.fptr = unspec->fptr;
             fptr.jlcall_api = unspec->jlcall_api;
             if (fptr.fptr && fptr.jlcall_api) {
@@ -1466,7 +1470,8 @@ void jl_extern_c(jl_function_t *f, jl_value_t *rt, jl_value_t *argt, char *name)
 extern "C" JL_DLLEXPORT
 void *jl_get_llvmf_defn(jl_method_instance_t *linfo, size_t world, bool getwrapper, bool optimize, const jl_cgparams_t params)
 {
-    if (jl_is_method(linfo->def.method) && linfo->def.method->source == NULL) {
+    if (jl_is_method(linfo->def.method) && linfo->def.method->source == NULL &&
+        linfo->def.method->generator == NULL) {
         // not a generic function
         return NULL;
     }
@@ -1476,7 +1481,7 @@ void *jl_get_llvmf_defn(jl_method_instance_t *linfo, size_t world, bool getwrapp
     if (!src || (jl_value_t*)src == jl_nothing) {
         src = jl_type_infer(&linfo, world, 0);
         if (!src && jl_is_method(linfo->def.method))
-            src = linfo->def.method->isstaged ? jl_code_for_staged(linfo) : (jl_code_info_t*)linfo->def.method->source;
+            src = linfo->def.method->generator ? jl_code_for_staged(linfo) : (jl_code_info_t*)linfo->def.method->source;
     }
     if ((jl_value_t*)src == jl_nothing)
         src = NULL;
@@ -1546,7 +1551,8 @@ void *jl_get_llvmf_defn(jl_method_instance_t *linfo, size_t world, bool getwrapp
 extern "C" JL_DLLEXPORT
 void *jl_get_llvmf_decl(jl_method_instance_t *linfo, size_t world, bool getwrapper, const jl_cgparams_t params)
 {
-    if (jl_is_method(linfo->def.method) && linfo->def.method->source == NULL) {
+    if (jl_is_method(linfo->def.method) && linfo->def.method->source == NULL &&
+        linfo->def.method->generator == NULL) {
         // not a generic function
         return NULL;
     }
@@ -1563,7 +1569,7 @@ void *jl_get_llvmf_decl(jl_method_instance_t *linfo, size_t world, bool getwrapp
             jl_code_info_t *src = NULL;
             src = jl_type_infer(&linfo, world, 0);
             if (!src) {
-                src = linfo->def.method->isstaged ? jl_code_for_staged(linfo) : (jl_code_info_t*)linfo->def.method->source;
+                src = linfo->def.method->generator ? jl_code_for_staged(linfo) : (jl_code_info_t*)linfo->def.method->source;
             }
             decls = jl_compile_linfo(&linfo, src, world, &params);
             linfo->functionObjectsDecls = decls;
diff --git a/src/dump.c b/src/dump.c
index 31c0fa6541add..e25b7f5b110f7 100644
--- a/src/dump.c
+++ b/src/dump.c
@@ -627,7 +627,6 @@ static void jl_serialize_value_(jl_serializer_state *s, jl_value_t *v, int as_li
         union jl_typemap_t *tf = &m->specializations;
         jl_serialize_value(s, tf->unknown);
         jl_serialize_value(s, (jl_value_t*)m->name);
-        write_int8(s->s, m->isstaged);
         jl_serialize_value(s, (jl_value_t*)m->file);
         write_int32(s->s, m->line);
         if (external_mt)
@@ -1396,7 +1395,6 @@ static jl_value_t *jl_deserialize_value_method(jl_serializer_state *s, jl_value_
     jl_gc_wb(m, m->specializations.unknown);
     m->name = (jl_sym_t*)jl_deserialize_value(s, NULL);
     jl_gc_wb(m, m->name);
-    m->isstaged = read_int8(s->s);
     m->file = (jl_sym_t*)jl_deserialize_value(s, NULL);
     m->line = read_int32(s->s);
     m->min_world = jl_world_counter;
diff --git a/src/gf.c b/src/gf.c
index 04fbae6bca875..64bcc801cc7b8 100644
--- a/src/gf.c
+++ b/src/gf.c
@@ -580,7 +580,6 @@ static void jl_cacheable_sig(
     int *const need_guard_entries,
     int *const makesimplesig)
 {
-    int8_t isstaged = definition->isstaged;
     assert(jl_is_tuple_type(type));
     size_t i, np = jl_nparams(type);
     for (i = 0; i < np; i++) {
@@ -593,7 +592,7 @@ static void jl_cacheable_sig(
             continue;
         }
 
-        if (isstaged) {
+        if (definition->generator) {
             // staged functions can't be optimized
             continue;
         }
@@ -697,7 +696,7 @@ JL_DLLEXPORT int jl_is_cacheable_sig(
     // compute whether this type signature is a possible return value from jl_cacheable_sig
     //return jl_cacheable_sig(type, NULL, definition->sig, definition, NULL, NULL);
 
-    if (definition->isstaged)
+    if (definition->generator)
         // staged functions can't be optimized
         // so assume the caller was intelligent about calling us
         return 1;
@@ -847,7 +846,7 @@ static jl_method_instance_t *cache_method(jl_methtable_t *mt, union jl_typemap_t
     // in general, here we want to find the biggest type that's not a
     // supertype of any other method signatures. so far we are conservative
     // and the types we find should be bigger.
-    if (!definition->isstaged && jl_nparams(type) > mt->max_args
+    if (definition->generator == NULL && jl_nparams(type) > mt->max_args
         && jl_va_tuple_kind((jl_datatype_t*)decl) == JL_VARARG_UNBOUND) {
         size_t i, nspec = mt->max_args + 2;
         jl_svec_t *limited = jl_alloc_svec(nspec);
@@ -1625,7 +1624,7 @@ jl_llvm_functions_t jl_compile_for_dispatch(jl_method_instance_t **pli, size_t w
         jl_options.compile_enabled == JL_OPTIONS_COMPILE_MIN) {
         // copy fptr from the template method definition
         jl_method_t *def = li->def.method;
-        if (jl_is_method(def) && !def->isstaged && def->unspecialized) {
+        if (jl_is_method(def) && def->unspecialized) {
             if (def->unspecialized->jlcall_api == 2) {
                 li->functionObjectsDecls.functionObject = NULL;
                 li->functionObjectsDecls.specFunctionObject = NULL;
diff --git a/src/interpreter.c b/src/interpreter.c
index 34066a5b781e5..19f4c576e00f1 100644
--- a/src/interpreter.c
+++ b/src/interpreter.c
@@ -640,14 +640,15 @@ jl_value_t *jl_interpret_call(jl_method_instance_t *lam, jl_value_t **args, uint
         return lam->inferred_const;
     jl_code_info_t *src = (jl_code_info_t*)lam->inferred;
     if (!src || (jl_value_t*)src == jl_nothing) {
-        if (lam->def.method->isstaged) {
+        if (lam->def.method->source) {
+            src = (jl_code_info_t*)lam->def.method->source;
+        }
+        else {
+            assert(lam->def.method->generator);
             src = jl_code_for_staged(lam);
             lam->inferred = (jl_value_t*)src;
             jl_gc_wb(lam, src);
         }
-        else {
-            src = (jl_code_info_t*)lam->def.method->source;
-        }
     }
     if (src && (jl_value_t*)src != jl_nothing) {
         src = jl_uncompress_ast(lam->def.method, (jl_array_t*)src);
diff --git a/src/jltypes.c b/src/jltypes.c
index f980c6125242a..acbb2bdbb3c26 100644
--- a/src/jltypes.c
+++ b/src/jltypes.c
@@ -1920,7 +1920,7 @@ void jl_init_types(void)
     jl_method_type =
         jl_new_datatype(jl_symbol("Method"), core,
                         jl_any_type, jl_emptysvec,
-                        jl_perm_symsvec(19,
+                        jl_perm_symsvec(18,
                             "name",
                             "module",
                             "file",
@@ -1938,9 +1938,8 @@ void jl_init_types(void)
                             "nargs",
                             "called",
                             "isva",
-                            "isstaged",
                             "pure"),
-                        jl_svec(19,
+                        jl_svec(18,
                             jl_sym_type,
                             jl_module_type,
                             jl_sym_type,
@@ -1958,7 +1957,6 @@ void jl_init_types(void)
                             jl_int32_type,
                             jl_int32_type,
                             jl_bool_type,
-                            jl_bool_type,
                             jl_bool_type),
                         0, 1, 9);
 
diff --git a/src/julia.h b/src/julia.h
index 497c7ddcbce45..64187ba019389 100644
--- a/src/julia.h
+++ b/src/julia.h
@@ -245,7 +245,7 @@ typedef struct _jl_method_t {
     jl_svec_t *sparam_syms;  // symbols giving static parameter names
     jl_value_t *source;  // original code template (jl_code_info_t, but may be compressed), null for builtins
     struct _jl_method_instance_t *unspecialized;  // unspecialized executable method instance, or null
-    struct _jl_method_instance_t *generator;  // executable code-generating function if isstaged
+    struct _jl_method_instance_t *generator;  // executable code-generating function if available
     jl_array_t *roots;  // pointers in generated code (shared to reduce memory), or null
 
     // cache of specializations of this method for invoke(), i.e.
@@ -256,7 +256,6 @@ typedef struct _jl_method_t {
     int32_t nargs;
     int32_t called;  // bit flags: whether each of the first 8 arguments is called
     uint8_t isva;
-    uint8_t isstaged;
     uint8_t pure;
 
 // hidden fields:
diff --git a/src/julia_internal.h b/src/julia_internal.h
index 2dc512d979cf4..cf5397f247bd7 100644
--- a/src/julia_internal.h
+++ b/src/julia_internal.h
@@ -342,7 +342,7 @@ STATIC_INLINE jl_value_t *jl_compile_method_internal(jl_generic_fptr_t *fptr,
             fptr->fptr = meth->unspecialized_ducttape;
             fptr->jlcall_api = 1;
             if (!fptr->fptr) {
-                if (jl_is_method(meth->def.method) && !meth->def.method->isstaged && meth->def.method->unspecialized) {
+                if (jl_is_method(meth->def.method) && meth->def.method->unspecialized) {
                     fptr->fptr = meth->def.method->unspecialized->fptr;
                     fptr->jlcall_api = meth->def.method->unspecialized->jlcall_api;
                     if (fptr->jlcall_api == 2) {
diff --git a/src/method.c b/src/method.c
index b5942c023e86e..219b225977fb7 100644
--- a/src/method.c
+++ b/src/method.c
@@ -267,8 +267,8 @@ JL_DLLEXPORT jl_code_info_t *jl_code_for_staged(jl_method_instance_t *linfo)
     jl_value_t *linenum = NULL;
     jl_svec_t *sparam_vals = env;
     jl_method_instance_t *generator = linfo->def.method->generator;
+    assert(generator != NULL);
     assert(linfo != generator);
-    assert(linfo->def.method->isstaged);
     jl_code_info_t *func = NULL;
     JL_GC_PUSH4(&ex, &linenum, &sparam_vals, &func);
     jl_ptls_t ptls = jl_get_ptls_states();
@@ -289,7 +289,7 @@ JL_DLLEXPORT jl_code_info_t *jl_code_for_staged(jl_method_instance_t *linfo)
 
         jl_array_t *argnames = jl_alloc_vec_any(linfo->def.method->nargs);
         jl_array_ptr_set(ex->args, 0, argnames);
-        jl_fill_argnames((jl_array_t*)linfo->def.method->source, argnames);
+        jl_fill_argnames((jl_array_t*)generator->inferred, argnames);
 
         // build the rest of the body to pass to expand
         jl_expr_t *scopeblock = jl_exprn(jl_symbol("scope-block"), 1);
@@ -466,7 +466,6 @@ JL_DLLEXPORT jl_method_t *jl_new_method_uninit(jl_module_t *module)
     m->line = 0;
     m->called = 0xff;
     m->invokes.unknown = NULL;
-    m->isstaged = 0;
     m->isva = 0;
     m->nargs = 0;
     m->traced = 0;
@@ -499,7 +498,6 @@ static jl_method_t *jl_new_method(
     m->sparam_syms = sparam_syms;
     root = (jl_value_t*)m;
     m->min_world = ++jl_world_counter;
-    m->isstaged = isstaged;
     m->name = name;
     m->sig = (jl_value_t*)sig;
     m->isva = isva;
@@ -510,6 +508,7 @@ static jl_method_t *jl_new_method(
         m->generator = jl_get_specialized(m, (jl_value_t*)jl_anytuple_type, jl_emptysvec);
         jl_gc_wb(m, m->generator);
         m->generator->inferred = (jl_value_t*)m->source;
+        m->source = NULL;
     }
 
 #ifdef RECORD_METHOD_ORDER
diff --git a/src/precompile.c b/src/precompile.c
index 6022d57d2852b..e45d950d508fc 100644
--- a/src/precompile.c
+++ b/src/precompile.c
@@ -239,7 +239,7 @@ static void _compile_all_deq(jl_array_t *found)
             jl_printf(JL_STDERR, " %d / %d\r", found_i + 1, found_l);
         jl_typemap_entry_t *ml = (jl_typemap_entry_t*)jl_array_ptr_ref(found, found_i);
         jl_method_t *m = ml->func.method;
-        if (m->isstaged)  // TODO: generic implementations of generated functions
+        if (m->source == NULL)  // TODO: generic implementations of generated functions
             continue;
         linfo = m->unspecialized;
         if (!linfo) {
@@ -274,7 +274,7 @@ static int compile_all_enq__(jl_typemap_entry_t *ml, void *env)
     jl_array_t *found = (jl_array_t*)env;
     // method definition -- compile template field
     jl_method_t *m = ml->func.method;
-    if (!m->isstaged &&
+    if (m->source &&
         (!m->unspecialized ||
          (m->unspecialized->functionObjectsDecls.functionObject == NULL &&
           m->unspecialized->jlcall_api != 2 &&