diff --git a/src/lib.rs b/src/lib.rs
index c880dbecb..6193d4a99 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -29,7 +29,7 @@ use crate::nixpacks::{
     nix::pkg::Pkg,
     plan::{generator::NixpacksBuildPlanGenerator, BuildPlan, PlanGenerator},
 };
-use anyhow::{bail, Result};
+use anyhow::Result;
 use nixpacks::plan::generator::GeneratePlanOptions;
 use providers::{
     clojure::ClojureProvider, crystal::CrystalProvider, csharp::CSharpProvider, dart::DartProvider,
@@ -93,12 +93,6 @@ pub fn create_docker_image(
     let mut generator = NixpacksBuildPlanGenerator::new(get_providers(), plan_options.clone());
     let plan = generator.generate_plan(&app, &environment)?;
 
-    if let Some(ref phase) = plan.start_phase {
-        if phase.cmd.is_none() && !build_options.no_error_without_start {
-            bail!("No start command could be found")
-        }
-    }
-
     let logger = Logger::new();
     let builder = DockerImageBuilder::new(logger, build_options.clone());
     builder.create_image(app.source.to_str().unwrap(), &plan, &environment)?;
diff --git a/src/nixpacks/builder/docker/docker_image_builder.rs b/src/nixpacks/builder/docker/docker_image_builder.rs
index 54d391500..37007cf83 100644
--- a/src/nixpacks/builder/docker/docker_image_builder.rs
+++ b/src/nixpacks/builder/docker/docker_image_builder.rs
@@ -48,6 +48,11 @@ impl ImageBuilder for DockerImageBuilder {
 
         println!("{}", plan.get_build_string()?);
 
+        let start = plan.start_phase.clone().unwrap_or_default();
+        if start.cmd.is_none() && !self.options.no_error_without_start {
+            bail!("No start command could be found")
+        }
+
         self.write_app(app_src, &output).context("Writing app")?;
         self.write_dockerfile(dockerfile, &output)
             .context("Writing Dockerfile")?;