diff --git a/src/gc-alloc-profiler.cpp b/src/gc-alloc-profiler.cpp
index 71ba4983923ae..612f42578728e 100644
--- a/src/gc-alloc-profiler.cpp
+++ b/src/gc-alloc-profiler.cpp
@@ -40,7 +40,8 @@ void push_raw_alloc(struct RawAllocProfile *profile, size_t type_tag, size_t byt
     } else {
         jl_array_ptr_1d_push(profile->alloc_types, (jl_value_t*)jl_nothing_type);
     }
-    // jl_array_ptr_1d_push(profile->alloc_sizes, bytes_allocated);
+    // TODO: push this onto this array without boxing it
+    jl_array_ptr_1d_push(profile->alloc_sizes, jl_box_uint64(bytes_allocated));
     jl_array_ptr_1d_push(profile->alloc_bts, (jl_value_t *)bt);
     jl_array_ptr_1d_push(profile->alloc_bt2s, (jl_value_t *)bt2);
 }
@@ -76,8 +77,6 @@ void _record_allocated_value(jl_value_t *val, size_t size) JL_NOTSAFEPOINT {
 
     // profile->type_address_by_value_address[(size_t)val] = (size_t)type;
 
-    auto bytes_allocated = 5; // TODO: where were we getting this from?
-
     g_alloc_profile_enabled = false;
     push_raw_alloc(profile, type_tag, size);
     g_alloc_profile_enabled = true;
diff --git a/stdlib/AllocProfile/src/AllocProfile.jl b/stdlib/AllocProfile/src/AllocProfile.jl
index 3e0e24e994735..e1c858fdfb7ab 100644
--- a/stdlib/AllocProfile/src/AllocProfile.jl
+++ b/stdlib/AllocProfile/src/AllocProfile.jl
@@ -13,7 +13,7 @@ const ExtendedEntryObj = Union{
 # matches RawAllocResults on the C side
 struct RawAllocProfile
     alloc_types::Vector{Ptr{Type}}
-    alloc_sizes::Vector{Csize_t}
+    alloc_sizes::Vector{Ptr{Csize_t}}
     alloc_bts::Vector{Vector{Ptr{Cvoid}}}
     alloc_bt2s::Vector{Vector{ExtendedEntryObj}}
 
@@ -135,15 +135,21 @@ function decode(raw_results::RawAllocProfile)::AllocResults
     cache = BacktraceCache()
     allocs = Vector{Alloc}()
 
-    @assert length(raw_results.alloc_bts) == length(raw_results.alloc_bt2s) == length(raw_results.alloc_types)
+    @assert length(raw_results.alloc_bts) ==
+        length(raw_results.alloc_bt2s) ==
+        length(raw_results.alloc_types) ==
+        length(raw_results.alloc_sizes)
 
     for i in 1:length(raw_results.alloc_bts)
         bt = raw_results.alloc_bts[i]
         bt2 = raw_results.alloc_bt2s[i]
-        type = load_type(raw_results.alloc_types[i])
+        type_tag = raw_results.alloc_types[i]
+        size = ccall(:jl_unbox_uint64, UInt64, (Ptr{Csize_t},), raw_results.alloc_sizes[i])
+
+        type = load_type(type_tag)
         back_trace = _reformat_bt_custom(bt, bt2)
         stack_trace = stacktrace_memoized(cache, back_trace)
-        size = 5 # TODO: grab this
+        
         push!(allocs, Alloc(
             type,
             stack_trace,