diff --git a/.github/workflows/cleanup-dependabot-prs.yml b/.github/workflows/cleanup-dependabot-prs.yml
index 423632ba8..5ff86630d 100644
--- a/.github/workflows/cleanup-dependabot-prs.yml
+++ b/.github/workflows/cleanup-dependabot-prs.yml
@@ -5,7 +5,7 @@ on:
   pull_request:
     types: [closed]
     branches:
-      - main
+      - master
 
 jobs:
   cleanup:
diff --git a/.github/workflows/merge-dependabot-prs.yml b/.github/workflows/merge-dependabot-prs.yml
index 3db1daccb..daba65f91 100644
--- a/.github/workflows/merge-dependabot-prs.yml
+++ b/.github/workflows/merge-dependabot-prs.yml
@@ -21,7 +21,7 @@ on:
         description: 'Base branch to merge into'
         required: false
         type: string
-        default: 'main'
+        default: 'master'
 
 jobs:
   merge-dependabot-prs:
@@ -54,7 +54,7 @@ jobs:
         run: |
           echo "Fetching open Dependabot PRs..."
           
-          BASE_BRANCH="${{ inputs.base_branch || 'main' }}"
+          BASE_BRANCH="${{ inputs.base_branch || 'master' }}"
           
           # Get all open Dependabot PRs with merge status
           ALL_PRS=$(gh pr list \
@@ -178,7 +178,7 @@ jobs:
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |
-          BASE_BRANCH="${{ inputs.base_branch || 'main' }}"
+          BASE_BRANCH="${{ inputs.base_branch || 'master' }}"
           COMBINED_BRANCH="merge-dependabot-updates-$(date +%Y%m%d-%H%M%S)"
           
           echo "branch=$COMBINED_BRANCH" >> $GITHUB_OUTPUT
@@ -240,7 +240,7 @@ jobs:
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |
-          BASE_BRANCH="${{ inputs.base_branch || 'main' }}"
+          BASE_BRANCH="${{ inputs.base_branch || 'master' }}"
           COMBINED_BRANCH="${{ steps.merge.outputs.branch }}"
           
           # Build PR body in a file to avoid shell escaping issues
diff --git a/kontroller/src/main/kotlin/no/ssb/kostra/program/FileLoader.kt b/kontroller/src/main/kotlin/no/ssb/kostra/program/FileLoader.kt
index f11f6a3a6..f102834d1 100644
--- a/kontroller/src/main/kotlin/no/ssb/kostra/program/FileLoader.kt
+++ b/kontroller/src/main/kotlin/no/ssb/kostra/program/FileLoader.kt
@@ -1,7 +1,11 @@
 package no.ssb.kostra.program
 
+import com.fasterxml.jackson.databind.DeserializationFeature
 import com.fasterxml.jackson.databind.ObjectMapper
+import com.fasterxml.jackson.databind.SerializationFeature
 import com.fasterxml.jackson.dataformat.yaml.YAMLFactory
+import com.fasterxml.jackson.dataformat.yaml.YAMLGenerator
+import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule
 import com.fasterxml.jackson.module.kotlin.readValue
 import com.fasterxml.jackson.module.kotlin.registerKotlinModule
 import no.ssb.kostra.program.extension.buildFieldDefinitions
@@ -10,7 +14,16 @@ import java.io.InputStreamReader
 import java.nio.file.NoSuchFileException
 
 object FileLoader {
-    val mapper = ObjectMapper(YAMLFactory()).registerKotlinModule()
+    val mapper: ObjectMapper =
+        ObjectMapper(
+            YAMLFactory()
+                .disable(YAMLGenerator.Feature.WRITE_DOC_START_MARKER)
+                .disable(YAMLGenerator.Feature.SPLIT_LINES)
+        )
+            .registerKotlinModule()                 // 👈 REQUIRED for Kotlin data classes
+            .registerModule(JavaTimeModule())      // 👈 REQUIRED for LocalDate / LocalDateTime
+            .disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS)
+            .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false)
 
     fun getResourceAsFieldDefinitionList(fileName: String): List<FieldDefinition> =
         getResource<FileDescription>(fileName).fields.buildFieldDefinitions()