diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index a18fff9..a0c46e5 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -10,7 +10,8 @@ If you plan to contribute to flatpak-github-actions, here's a couple of things t
 
 For more details, we recommend looking the extensive guide at [Creating a JavaScript action](https://docs.github.com/en/actions/creating-actions/creating-a-javascript-action#prerequisites)
 
-Once you have modified the `index.js` of either `flatpak-builder` or `flat-manager` action. Make sure to compile the file to the `dist` directory. You can do so with
+Once you have modified the `index.js` of either `flatpak-builder` or `flat-manager` action, make sure to compile the file to the `dist` directory. 
+Note: You should have already installed the npm packages of both `flatpak-builder` and `flat-manager`, with yarn. 
 
 ```shell
 ncc build ./flatpak-builder/index.js -o ./flatpak-builder/dist/
diff --git a/README.md b/README.md
index faa4749..6de40fe 100644
--- a/README.md
+++ b/README.md
@@ -56,6 +56,7 @@ jobs:
 | `arch` | Specifies the CPU architecture to build for | Optional | `x86_64` |
 | `mirror-screenshots-url` | Specifies the URL to mirror screenshots | Optional | - |
 | `gpg-sign` | The key to sign the package | Optional | - |
+| `keep-build-dirs` | Keep build directories after the build finishes (passes `--keep-build-dirs` to flatpak-builder). Useful for debugging intermediate files. | Optional | `false` |
 | `verbose` | Enable verbosity | Optional | `false` |
 | `upload-artifact` | Whether to upload the resulting bundle or not as an artifact | Optional | `true` |
 
diff --git a/flatpak-builder/action.yml b/flatpak-builder/action.yml
index a058495..901f937 100644
--- a/flatpak-builder/action.yml
+++ b/flatpak-builder/action.yml
@@ -56,6 +56,13 @@ inputs:
       Defines the cache-key to use.
       Defaults to flatpak-builder-${arch}-${sha256(manifestPath)}
     required: false
+  keep-build-dirs:
+    description: >
+      Keep build directories after the build finishes, passing `--keep-build-dirs` flag
+      to flatpak-builder. 
+      Possible values: true, enabled, yes, y. Defaults to false.
+    required: false
+    default: "false"
   branch:
     description: The flatpak branch.
     default: "master"
diff --git a/flatpak-builder/dist/index.js b/flatpak-builder/dist/index.js
index 20d0d29..61d11ca 100644
--- a/flatpak-builder/dist/index.js
+++ b/flatpak-builder/dist/index.js
@@ -51,6 +51,8 @@ class Configuration {
     this.mirrorScreenshotsUrl = core.getInput('mirror-screenshots-url')
     // The key to sign the package
     this.gpgSign = core.getInput('gpg-sign')
+    // Keep build directories after the build (pass --keep-build-dirs)
+    this.keepBuildDirs = core.getBooleanInput('keep-build-dirs')
     // Modified manifest path
     this.modifiedManifestPath = path.join(
       path.dirname(this.manifestPath),
@@ -232,6 +234,9 @@ const build = async (manifest, manifestPath, cacheHitKey, config) => {
     `--default-branch=${branch}`,
     `--arch=${config.arch}`
   ]
+  if (config.keepBuildDirs) {
+    args.push('--keep-build-dirs')
+  }
   if (config.cacheBuildDir) {
     args.push('--ccache')
   }
diff --git a/flatpak-builder/index.js b/flatpak-builder/index.js
index 0ff63ea..2893245 100644
--- a/flatpak-builder/index.js
+++ b/flatpak-builder/index.js
@@ -45,6 +45,8 @@ class Configuration {
     this.mirrorScreenshotsUrl = core.getInput('mirror-screenshots-url')
     // The key to sign the package
     this.gpgSign = core.getInput('gpg-sign')
+    // Keep build directories after the build (pass --keep-build-dirs)
+    this.keepBuildDirs = core.getBooleanInput('keep-build-dirs')
     // Modified manifest path
     this.modifiedManifestPath = path.join(
       path.dirname(this.manifestPath),
@@ -226,6 +228,9 @@ const build = async (manifest, manifestPath, cacheHitKey, config) => {
     `--default-branch=${branch}`,
     `--arch=${config.arch}`
   ]
+  if (config.keepBuildDirs) {
+    args.push('--keep-build-dirs')
+  }
   if (config.cacheBuildDir) {
     args.push('--ccache')
   }