diff --git a/src/core/ascii_85_stream.js b/src/core/ascii_85_stream.js
new file mode 100644
index 000000000..78f13afd9
--- /dev/null
+++ b/src/core/ascii_85_stream.js
@@ -0,0 +1,105 @@
+/* Copyright 2012 Mozilla Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/* eslint-disable no-var */
+
+import { DecodeStream } from "./stream.js";
+import { isWhiteSpace } from "./core_utils.js";
+
+var Ascii85Stream = (function Ascii85StreamClosure() {
+  // eslint-disable-next-line no-shadow
+  function Ascii85Stream(str, maybeLength) {
+    this.str = str;
+    this.dict = str.dict;
+    this.input = new Uint8Array(5);
+
+    // Most streams increase in size when decoded, but Ascii85 streams
+    // typically shrink by ~20%.
+    if (maybeLength) {
+      maybeLength = 0.8 * maybeLength;
+    }
+    DecodeStream.call(this, maybeLength);
+  }
+
+  Ascii85Stream.prototype = Object.create(DecodeStream.prototype);
+
+  Ascii85Stream.prototype.readBlock = function Ascii85Stream_readBlock() {
+    var TILDA_CHAR = 0x7e; // '~'
+    var Z_LOWER_CHAR = 0x7a; // 'z'
+    var EOF = -1;
+
+    var str = this.str;
+
+    var c = str.getByte();
+    while (isWhiteSpace(c)) {
+      c = str.getByte();
+    }
+
+    if (c === EOF || c === TILDA_CHAR) {
+      this.eof = true;
+      return;
+    }
+
+    var bufferLength = this.bufferLength,
+      buffer;
+    var i;
+
+    // special code for z
+    if (c === Z_LOWER_CHAR) {
+      buffer = this.ensureBuffer(bufferLength + 4);
+      for (i = 0; i < 4; ++i) {
+        buffer[bufferLength + i] = 0;
+      }
+      this.bufferLength += 4;
+    } else {
+      var input = this.input;
+      input[0] = c;
+      for (i = 1; i < 5; ++i) {
+        c = str.getByte();
+        while (isWhiteSpace(c)) {
+          c = str.getByte();
+        }
+
+        input[i] = c;
+
+        if (c === EOF || c === TILDA_CHAR) {
+          break;
+        }
+      }
+      buffer = this.ensureBuffer(bufferLength + i - 1);
+      this.bufferLength += i - 1;
+
+      // partial ending;
+      if (i < 5) {
+        for (; i < 5; ++i) {
+          input[i] = 0x21 + 84;
+        }
+        this.eof = true;
+      }
+      var t = 0;
+      for (i = 0; i < 5; ++i) {
+        t = t * 85 + (input[i] - 0x21);
+      }
+
+      for (i = 3; i >= 0; --i) {
+        buffer[bufferLength + i] = t & 0xff;
+        t >>= 8;
+      }
+    }
+  };
+
+  return Ascii85Stream;
+})();
+
+export { Ascii85Stream };
diff --git a/src/core/parser.js b/src/core/parser.js
index 048deae7f..90796ad22 100644
--- a/src/core/parser.js
+++ b/src/core/parser.js
@@ -13,12 +13,6 @@
  * limitations under the License.
  */
 
-import {
-  Ascii85Stream,
-  FlateStream,
-  NullStream,
-  PredictorStream,
-} from "./stream.js";
 import {
   assert,
   bytesToString,
@@ -39,7 +33,9 @@ import {
   Name,
   Ref,
 } from "./primitives.js";
+import { FlateStream, NullStream, PredictorStream } from "./stream.js";
 import { isWhiteSpace, MissingDataException } from "./core_utils.js";
+import { Ascii85Stream } from "./ascii_85_stream.js";
 import { AsciiHexStream } from "./ascii_hex_stream.js";
 import { CCITTFaxStream } from "./ccitt_stream.js";
 import { Jbig2Stream } from "./jbig2_stream.js";
diff --git a/src/core/stream.js b/src/core/stream.js
index 1c09cb8aa..9005d02bf 100644
--- a/src/core/stream.js
+++ b/src/core/stream.js
@@ -22,7 +22,6 @@
 
 import { FormatError, stringToBytes, unreachable } from "../shared/util.js";
 import { isDict } from "./primitives.js";
-import { isWhiteSpace } from "./core_utils.js";
 
 var Stream = (function StreamClosure() {
   // eslint-disable-next-line no-shadow
@@ -996,91 +995,6 @@ var DecryptStream = (function DecryptStreamClosure() {
   return DecryptStream;
 })();
 
-var Ascii85Stream = (function Ascii85StreamClosure() {
-  // eslint-disable-next-line no-shadow
-  function Ascii85Stream(str, maybeLength) {
-    this.str = str;
-    this.dict = str.dict;
-    this.input = new Uint8Array(5);
-
-    // Most streams increase in size when decoded, but Ascii85 streams
-    // typically shrink by ~20%.
-    if (maybeLength) {
-      maybeLength = 0.8 * maybeLength;
-    }
-    DecodeStream.call(this, maybeLength);
-  }
-
-  Ascii85Stream.prototype = Object.create(DecodeStream.prototype);
-
-  Ascii85Stream.prototype.readBlock = function Ascii85Stream_readBlock() {
-    var TILDA_CHAR = 0x7e; // '~'
-    var Z_LOWER_CHAR = 0x7a; // 'z'
-    var EOF = -1;
-
-    var str = this.str;
-
-    var c = str.getByte();
-    while (isWhiteSpace(c)) {
-      c = str.getByte();
-    }
-
-    if (c === EOF || c === TILDA_CHAR) {
-      this.eof = true;
-      return;
-    }
-
-    var bufferLength = this.bufferLength,
-      buffer;
-    var i;
-
-    // special code for z
-    if (c === Z_LOWER_CHAR) {
-      buffer = this.ensureBuffer(bufferLength + 4);
-      for (i = 0; i < 4; ++i) {
-        buffer[bufferLength + i] = 0;
-      }
-      this.bufferLength += 4;
-    } else {
-      var input = this.input;
-      input[0] = c;
-      for (i = 1; i < 5; ++i) {
-        c = str.getByte();
-        while (isWhiteSpace(c)) {
-          c = str.getByte();
-        }
-
-        input[i] = c;
-
-        if (c === EOF || c === TILDA_CHAR) {
-          break;
-        }
-      }
-      buffer = this.ensureBuffer(bufferLength + i - 1);
-      this.bufferLength += i - 1;
-
-      // partial ending;
-      if (i < 5) {
-        for (; i < 5; ++i) {
-          input[i] = 0x21 + 84;
-        }
-        this.eof = true;
-      }
-      var t = 0;
-      for (i = 0; i < 5; ++i) {
-        t = t * 85 + (input[i] - 0x21);
-      }
-
-      for (i = 3; i >= 0; --i) {
-        buffer[bufferLength + i] = t & 0xff;
-        t >>= 8;
-      }
-    }
-  };
-
-  return Ascii85Stream;
-})();
-
 var NullStream = (function NullStreamClosure() {
   // eslint-disable-next-line no-shadow
   function NullStream() {
@@ -1093,7 +1007,6 @@ var NullStream = (function NullStreamClosure() {
 })();
 
 export {
-  Ascii85Stream,
   DecodeStream,
   DecryptStream,
   FlateStream,