diff --git a/utils/zerovec/src/map2d/databake.rs b/utils/zerovec/src/map2d/databake.rs
index b505539772e..c5b9aca5463 100644
--- a/utils/zerovec/src/map2d/databake.rs
+++ b/utils/zerovec/src/map2d/databake.rs
@@ -52,7 +52,7 @@ fn test_baked_map() {
             crate::ZeroMap2d::from_parts_unchecked(
                 unsafe {
                     crate::VarZeroVec::from_bytes_unchecked(
-                        b"arcaz\0cu\0en\0ff\0grckk\0ku\0ky\0lifmanmn\0pa\0palsd\0tg\0ug\0unruz\0yuezh\0"
+                        b"\x0E\0\0\0\0\0\x05\0\x07\0\t\0\x0B\0\x10\0\x12\0\x14\0\x1C\0\x1E\0#\0%\0'\0,\0arcazcuenffgrckkkukylifmanmnpapalsdtgugunruzyuezh"
                     )
                 },
                 unsafe {
@@ -62,12 +62,12 @@ fn test_baked_map() {
                 },
                 unsafe {
                     crate::VarZeroVec::from_bytes_unchecked(
-                        b"NbatPalmArabGlagShawAdlmLinbArabArabYeziArabLatnLimbNkooMongArabPhlpDevaKhojSindArabCyrlDevaArabHansBopoHanbHant"
+                        b"\x1C\0\0\0\0\0\x04\0\x08\0\x0C\0\x10\0\x14\0\x18\0\x1C\0 \0$\0(\0,\x000\x004\08\0<\0@\0D\0H\0L\0P\0T\0X\0\\\0`\0d\0h\0l\0NbatPalmArabGlagShawAdlmLinbArabArabYeziArabLatnLimbNkooMongArabPhlpDevaKhojSindArabCyrlDevaArabHansBopoHanbHant"
                     )
                 },
                 unsafe {
                     crate::VarZeroVec::from_bytes_unchecked(
-                        b"JO\0SY\0IR\0BG\0GB\0GN\0GR\0CN\0IQ\0GE\0CN\0TR\0IN\0GN\0CN\0PK\0CN\0IN\0IN\0IN\0PK\0KZ\0NP\0AF\0CN\0TW\0TW\0TW\0"
+                        b"\x1C\0\0\0\0\0\x02\0\x04\0\x06\0\x08\0\n\0\x0C\0\x0E\0\x10\0\x12\0\x14\0\x16\0\x18\0\x1A\0\x1C\0\x1E\0 \0\"\0$\0&\0(\0*\0,\0.\x000\x002\x004\x006\0JOSYIRBGGBGNGRCNIQGECNTRINGNCNPKCNINININPKKZNPAFCNTWTWTW"
                     )
                 },
             )
@@ -85,7 +85,7 @@ fn test_baked_borrowed_map() {
             crate::maps::ZeroMap2dBorrowed::from_parts_unchecked(
                 unsafe {
                     crate::VarZeroSlice::from_bytes_unchecked(
-                        b"arcaz\0cu\0en\0ff\0grckk\0ku\0ky\0lifmanmn\0pa\0palsd\0tg\0ug\0unruz\0yuezh\0"
+                        b"\x0E\0\0\0\0\0\x05\0\x07\0\t\0\x0B\0\x10\0\x12\0\x14\0\x1C\0\x1E\0#\0%\0'\0,\0arcazcuenffgrckkkukylifmanmnpapalsdtgugunruzyuezh"
                     )
                 },
                 unsafe {
@@ -95,12 +95,12 @@ fn test_baked_borrowed_map() {
                 },
                 unsafe {
                     crate::VarZeroSlice::from_bytes_unchecked(
-                        b"NbatPalmArabGlagShawAdlmLinbArabArabYeziArabLatnLimbNkooMongArabPhlpDevaKhojSindArabCyrlDevaArabHansBopoHanbHant"
+                        b"\x1C\0\0\0\0\0\x04\0\x08\0\x0C\0\x10\0\x14\0\x18\0\x1C\0 \0$\0(\0,\x000\x004\08\0<\0@\0D\0H\0L\0P\0T\0X\0\\\0`\0d\0h\0l\0NbatPalmArabGlagShawAdlmLinbArabArabYeziArabLatnLimbNkooMongArabPhlpDevaKhojSindArabCyrlDevaArabHansBopoHanbHant"
                     )
                 },
                 unsafe {
                     crate::VarZeroSlice::from_bytes_unchecked(
-                        b"JO\0SY\0IR\0BG\0GB\0GN\0GR\0CN\0IQ\0GE\0CN\0TR\0IN\0GN\0CN\0PK\0CN\0IN\0IN\0IN\0PK\0KZ\0NP\0AF\0CN\0TW\0TW\0TW\0"
+                        b"\x1C\0\0\0\0\0\x02\0\x04\0\x06\0\x08\0\n\0\x0C\0\x0E\0\x10\0\x12\0\x14\0\x16\0\x18\0\x1A\0\x1C\0\x1E\0 \0\"\0$\0&\0(\0*\0,\0.\x000\x002\x004\x006\0JOSYIRBGGBGNGRCNIQGECNTRINGNCNPKCNINININPKKZNPAFCNTWTWTW"
                     )
                 },
             )
diff --git a/utils/zerovec/src/varzerovec/owned.rs b/utils/zerovec/src/varzerovec/owned.rs
index 76de4876097..0990a5d91d5 100644
--- a/utils/zerovec/src/varzerovec/owned.rs
+++ b/utils/zerovec/src/varzerovec/owned.rs
@@ -279,7 +279,7 @@ impl<T: VarULE + ?Sized, F: VarZeroVecFormat> VarZeroVecOwned<T, F> {
                     any::type_name::<F>()
                 );
             }
-            self.entire_slice.reserve(shift as usize);
+            self.entire_slice.resize(new_slice_len, 0);
         }
 
         // Now that we've ensured there's enough space, we can shift the data around.
@@ -287,6 +287,7 @@ impl<T: VarULE + ?Sized, F: VarZeroVecFormat> VarZeroVecOwned<T, F> {
             // Note: There are no references introduced between pointer creation and pointer use, and all
             //       raw pointers are derived from a single &mut. This preserves pointer provenance.
             let slice_range = self.entire_slice.as_mut_ptr_range();
+            let old_slice_end = slice_range.start.add(slice_len);
             let data_start = slice_range
                 .start
                 .add(LENGTH_WIDTH + METADATA_WIDTH + len * F::INDEX_WIDTH);
@@ -316,7 +317,7 @@ impl<T: VarULE + ?Sized, F: VarZeroVecFormat> VarZeroVecOwned<T, F> {
 
             // Shift data after the element to its new position.
             shift_bytes(
-                prev_element_p.end..slice_range.end,
+                prev_element_p.end..old_slice_end,
                 prev_element_p
                     .start
                     .offset((new_size as i64 + index_shift) as isize),