diff --git a/CHANGELOG.md b/CHANGELOG.md
index 46c50453b..4ce0e0fd6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -22,6 +22,8 @@
 
 * `NextflowVDSL3Platform`: Fix 'Module scriptPath has not been defined yet' error when Nextflow>=22.10 (#269).
 
+* `config inject`: Doesn't work when `must_exist == true` (#273).
+
 ## DEPRECATION
 
 * `DockerRequirements`: The `resources:` setting has been deprecated and will be removed in Viash 0.7.0. Please use `copy:` instead.
diff --git a/src/main/scala/io/viash/platforms/DebugPlatform.scala b/src/main/scala/io/viash/platforms/DebugPlatform.scala
index 530fd0da0..3028abd22 100644
--- a/src/main/scala/io/viash/platforms/DebugPlatform.scala
+++ b/src/main/scala/io/viash/platforms/DebugPlatform.scala
@@ -63,6 +63,12 @@ case class DebugPlatform(
                 arg.copy(required = false, default = One("value"), choices = Nil)
               case a => a
             }
+            // also turn off must_exist if it is set to true
+            .map{
+              case arg: FileArgument if arg.must_exist =>
+                arg.copy(must_exist = false)
+              case a => a
+            }
             .map{Right(_)}
         )
       }