diff --git a/.github/actions/gradle-and-sha/action.yml b/.github/actions/gradle-and-sha/action.yml
index 4c0bcd145..108097700 100644
--- a/.github/actions/gradle-and-sha/action.yml
+++ b/.github/actions/gradle-and-sha/action.yml
@@ -23,9 +23,12 @@ runs:
     - name: "Rename output file"
       shell: bash
       run: |
-        ls build/*/*
         mv ${{ inputs.intermediate-filepath }} ${{ inputs.final-filepath }}
 
-    - name: "Generate SHA512"
+    - name: "Generate SHA512. If ZIP, it will also extract to avoid timestamp-mingling."
       shell: bash
-      run: ./.github/workflows/sha.sh ${{ runner.os }} ${{ inputs.final-filepath }} 512
+      run: |
+        ./.github/workflows/sha.sh ${{ inputs.final-filepath }} ${{ runner.os }} 512 > ${{ inputs.final-finalpath }}.sha512
+        if [ "${{ inputs.intermediate-filepath }}" == "*zip" ]; then
+          ./.github/workflows/sha-of-zip.sh ${{ inputs.final-filepath }} ${{ runner.os }} 512 > ${{ inputs.final-finalpath }}.golden.sha512
+        fi
diff --git a/.github/actions/zip/action.yml b/.github/actions/zip/action.yml
index 651a93558..7c70c845c 100644
--- a/.github/actions/zip/action.yml
+++ b/.github/actions/zip/action.yml
@@ -1,5 +1,5 @@
 name: "Create zip of a directory"
-description: "Cross-platform helper: creates SHA512"
+description: "Cross-platform helper: creates a zip archive"
 
 inputs:
   input:
@@ -20,11 +20,5 @@ runs:
       run: ${{ inputs.command }}
 
     - name: "Generate zip for Linux"
-      if: runner.os == 'Linux' || runner.os == 'MacOS'
       shell: bash
       run: zip -r ${{inputs.zipFilename}} ${{inputs.input}}
-
-    - name: "Generate zip for Windows"
-      if: runner.os == 'Windows'
-      shell: powershell
-      run: Compress-Archive -Path ${{inputs.input}} -Destination ${{inputs.zipFilename}}
diff --git a/.github/workflows/generate-dependency-hashes.sh b/.github/workflows/generate-dependency-hashes.sh
index cdc743b7d..7bd77d114 100755
--- a/.github/workflows/generate-dependency-hashes.sh
+++ b/.github/workflows/generate-dependency-hashes.sh
@@ -10,7 +10,7 @@ parentPath=$( cd "$(dirname "${BASH_SOURCE[0]}")" ; pwd -P )
 
 echo "Filename, SHA-1 Checksum, SHA-256 Checksum, Maven Dependency URL, Direct URL to SHA-1, Direct URL to SHA-256"
 cd ~/.gradle/caches/modules-2/files-2.1
-for filename in $(find  * -type f); do
+for filename in $(find * -type f); do
     # filename is of format, with dot-separated org:
     # <org>/<dependency-name>/<version>/<sha-1>/<dependency-name>-<version>.<ext>
     # friendly URL is of format, with dot-separated org:
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index deb67a5d2..2db27da25 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -97,7 +97,8 @@ jobs:
 
       - name: "Generate SHA512 for plugins cache"
         shell: bash
-        run: ./.github/workflows/sha.sh ${{steps.cachefn.outputs.FILEPATH}} ${{ runner.os }} 512
+        run: |
+          ./.github/workflows/sha-of-zip.sh ${{steps.cachefn.outputs.FILEPATH}} ${{ runner.os }} 512 
 
       - name: "Prepare keychain"
         if: matrix.os == 'macOS-latest'
@@ -152,10 +153,12 @@ jobs:
           path: |
             ${{ github.workspace }}/${{ steps.zipfn.outputs.FILEPATH }}
             ${{ github.workspace }}/${{ steps.zipfn.outputs.FILEPATH }}.sha512
+            ${{ github.workspace }}/${{ steps.zipfn.outputs.FILEPATH }}.golden.sha512
             ${{ github.workspace }}/${{ steps.exefn.outputs.FILEPATH }}
             ${{ github.workspace }}/${{ steps.exefn.outputs.FILEPATH }}.sha512
             ${{ github.workspace }}/${{steps.cachefn.outputs.FILEPATH}}
             ${{ github.workspace }}/${{steps.cachefn.outputs.FILEPATH}}.sha512
+            ${{ github.workspace }}/${{steps.cachefn.outputs.FILEPATH}}.golden.sha512
           retention-days: 1
 
       - name: "Upload binaries to release"
diff --git a/.github/workflows/sha-of-zip.sh b/.github/workflows/sha-of-zip.sh
new file mode 100755
index 000000000..d15ce5997
--- /dev/null
+++ b/.github/workflows/sha-of-zip.sh
@@ -0,0 +1,41 @@
+#!/bin/bash
+# Unzips the given zip file, then generates a checksum of the zip file that ignores
+# the timestamps by extracting it and SHA'ing a file of all SHAs. This is not recursive:-
+# zips within the zip will not be extracted, and therefore the timestamps of the "inner" zip
+# will be a part of the hash.
+# Usage: ./sha-of-zip.sh <zipFilepath> <OS: Windows, MacOS, or Linux> <sha version: 1, 256, or 512>
+set -e
+
+zipFilepath=$1
+os=$2
+a=$3
+
+echo parentpath
+parentPath=$( cd "$(dirname "${BASH_SOURCE[0]}")" ; pwd -P )
+
+# Make a temporary directory to extract zip, and a temporary file to hold SHAs
+echo temp1
+tempDirectory=$(mktemp -d)
+echo temp2
+tempAllChecksumsFile=$(mktemp)
+echo temp3
+touch $tempAllChecksumsFile
+
+# Extract the zip
+echo unzipy
+unzip -q $zipFilepath -d $tempDirectory
+
+# Get a checksum for each file in the zip
+echo tempcd
+cd $tempDirectory
+echo foreach
+for filename in $(find * -type f | sort); do
+  echo hcheck
+  checksum=$($parentPath/sha.sh $filename $os $a)
+  echo sum
+  echo $checksum >> $tempAllChecksumsFile
+done
+
+# Echo the checksum of the checksums
+echo sumitall
+echo $($parentPath/sha.sh $tempAllChecksumsFile $os $a)
diff --git a/.github/workflows/sha.sh b/.github/workflows/sha.sh
index e36b0b3f9..89fe9ba93 100755
--- a/.github/workflows/sha.sh
+++ b/.github/workflows/sha.sh
@@ -8,7 +8,6 @@ filename=$1
 os=$2
 a=$3
 
-
 if [ $os == 'Windows' ]; then
     echo $(certutil -hashfile $filename SHA$a | sed -n 2p)
 elif [ $os == 'Linux' ]; then
@@ -16,3 +15,4 @@ elif [ $os == 'Linux' ]; then
 else
     echo $(shasum -a $a $filename | cut -f1 -d" ")
 fi
+
diff --git a/build.gradle b/build.gradle
index cb3cd2a9c..09c2579cb 100644
--- a/build.gradle
+++ b/build.gradle
@@ -236,3 +236,11 @@ tasks.jlink.doLast {
         into JLINK_DIR + "/sample_input"
     }
 }
+
+// Ensure reproducible hashes
+tasks.withType(AbstractArchiveTask) {
+    preserveFileTimestamps = false
+    reproducibleFileOrder = true
+    dirMode = 0755
+    fileMode = 0644
+}