diff --git a/libraries/libmesosphere/source/init/kern_init_slab_setup.cpp b/libraries/libmesosphere/source/init/kern_init_slab_setup.cpp
index 01a580c29..5737afea7 100644
--- a/libraries/libmesosphere/source/init/kern_init_slab_setup.cpp
+++ b/libraries/libmesosphere/source/init/kern_init_slab_setup.cpp
@@ -127,10 +127,14 @@ namespace ams::kern::init {
             size += util::AlignUp(sizeof(NAME) * (COUNT), alignof(void *)); \
         });
 
-        /* NOTE: This can't be used right now because we don't have all these types implemented. */
-        /* Once we do, uncomment the following and stop using the hardcoded size. */
+        /* Add the size required for each slab. */
         FOREACH_SLAB_TYPE(ADD_SLAB_SIZE)
 
+        #undef ADD_SLAB_SIZE
+
+        /* Add the reserved size. */
+        size += SlabRegionReservedSize;
+
         return size;
     }
 
diff --git a/mesosphere/kernel/source/arch/arm64/init/kern_init_core.cpp b/mesosphere/kernel/source/arch/arm64/init/kern_init_core.cpp
index c13beb815..54ec9c055 100644
--- a/mesosphere/kernel/source/arch/arm64/init/kern_init_core.cpp
+++ b/mesosphere/kernel/source/arch/arm64/init/kern_init_core.cpp
@@ -156,7 +156,7 @@ namespace ams::kern::init {
         const size_t resource_region_size = GetResourceRegionSize();
 
         /* Determine the size of the slab region. */
-        const size_t slab_region_size = CalculateTotalSlabHeapSize();
+        const size_t slab_region_size = util::AlignUp(CalculateTotalSlabHeapSize(), PageSize);
         MESOSPHERE_INIT_ABORT_UNLESS(slab_region_size <= resource_region_size);
 
         /* Setup the slab region. */