diff --git a/Cargo.lock b/Cargo.lock
index df394d8aae..9874d44b06 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -694,6 +694,11 @@ dependencies = [
  "vcpkg 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "linked-hash-map"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "lock_api"
 version = "0.1.5"
@@ -1496,10 +1501,10 @@ version = "0.0.1-dev"
 dependencies = [
  "cc 1.0.45 (registry+https://github.com/rust-lang/crates.io-index)",
  "chrono 0.4.9 (registry+https://github.com/rust-lang/crates.io-index)",
- "indexmap 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.62 (registry+https://github.com/rust-lang/crates.io-index)",
  "libpng-sys 1.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "libz-sys 1.0.25 (registry+https://github.com/rust-lang/crates.io-index)",
+ "linked-hash-map 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "md-5 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "sha2 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2050,6 +2055,7 @@ dependencies = [
 "checksum libc 0.2.62 (registry+https://github.com/rust-lang/crates.io-index)" = "34fcd2c08d2f832f376f4173a231990fa5aef4e99fb569867318a227ef4c06ba"
 "checksum libpng-sys 1.1.8 (registry+https://github.com/rust-lang/crates.io-index)" = "939658d8a33e52645ecfdc42500285c8b0fdeb26df10677c32abd13a1fc1d70c"
 "checksum libz-sys 1.0.25 (registry+https://github.com/rust-lang/crates.io-index)" = "2eb5e43362e38e2bca2fd5f5134c4d4564a23a5c28e9b95411652021a8675ebe"
+"checksum linked-hash-map 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)" = "ae91b68aebc4ddb91978b11a1b02ddd8602a05ec19002801c5666000e05e0f83"
 "checksum lock_api 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "62ebf1391f6acad60e5c8b43706dde4582df75c06698ab44511d15016bc2442c"
 "checksum log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)" = "14b6052be84e6b71ab17edffc2eeabf5c2c3ae1fdb464aae35ac50c67a44e1f7"
 "checksum malloc_buf 0.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "62bb907fe88d54d8d9ce32a3cceab4218ed2f6b7d35617cafe9adf84e43919cb"
diff --git a/dpx/Cargo.toml b/dpx/Cargo.toml
index 7b0cd56255..81d918530d 100644
--- a/dpx/Cargo.toml
+++ b/dpx/Cargo.toml
@@ -15,7 +15,7 @@ md-5 = "0.8.0"
 sha2 = "0.8.0"
 rand = "0.7.2"
 chrono = "0.4.9"
-indexmap = "1.3.0"
+linked-hash-map = "0.5.2"
 
 [features]
 default = ['libz-sys']
diff --git a/dpx/src/dpx_pdfobj.rs b/dpx/src/dpx_pdfobj.rs
index b26f8d4036..95e999de10 100644
--- a/dpx/src/dpx_pdfobj.rs
+++ b/dpx/src/dpx_pdfobj.rs
@@ -222,12 +222,12 @@ pub struct xref_entry {
     pub indirect: PdfObjRef,
 }
 
-use indexmap::IndexMap;
+use linked_hash_map::LinkedHashMap;
 
 #[derive(Clone)]
 #[repr(C)]
 pub struct PdfDict {
-    inner: IndexMap<PdfName, PdfObjRef>,
+    inner: LinkedHashMap<PdfName, PdfObjRef>,
 }
 
 impl PdfDict {
@@ -1186,7 +1186,7 @@ unsafe fn write_dict(dict: &PdfDict, handle: &mut OutputHandleWrapper) {
 pub fn pdf_new_dict() -> PdfObjRef {
     safe_new_obj(PdfObjType::DICT, |object| {
         let boxed = Box::new(PdfDict {
-            inner: IndexMap::new(),
+            inner: LinkedHashMap::new(),
         });
         object.data = Box::into_raw(boxed) as *mut libc::c_void;
     })
@@ -1194,7 +1194,7 @@ pub fn pdf_new_dict() -> PdfObjRef {
 
 unsafe fn release_dict(mut data: *mut PdfDict) {
     let mut boxed = Box::from_raw(data);
-    for (_k, v) in boxed.inner.drain(..) {
+    for (_k, &v) in boxed.inner.iter() {
         unsafe {
             pdf_release_obj(v);
         }
@@ -1228,12 +1228,12 @@ pub unsafe extern "C" fn pdf_merge_dict(dict1: &mut pdf_obj, dict2: &pdf_obj) {
     let dict2 = dict2.get_dict();
     for (k, &v) in dict2.inner.iter() {
         let linked = pdf_link_obj(v);
-        dict1.inner.entry(k.clone())
-            .and_modify(|existing| {
-                let existing = mem::replace(existing, linked);
-                pdf_release_obj(existing);
-            })
-            .or_insert(linked);
+        if let Some(existing) = dict1.inner.get_mut(k) {
+            let existing = mem::replace(existing, linked);
+            pdf_release_obj(existing);
+        } else {
+            dict1.inner.insert(k.clone(), linked);
+        }
     }
 }