diff --git a/src/deb/local.rs b/src/deb/local.rs
index 6270a10..23d684d 100644
--- a/src/deb/local.rs
+++ b/src/deb/local.rs
@@ -188,17 +188,7 @@ pub async fn build(
 
     // Install injected packages if specified
     if let Some(packages) = inject_packages {
-        log::info!("Installing injected packages: {:?}", packages);
-        let mut cmd = ctx.command("apt-get");
-        cmd.envs(env.clone())
-            .arg("-y")
-            .arg("--allow-downgrades")
-            .arg("install")
-            .args(packages);
-        let status = cmd.status()?;
-        if !status.success() {
-            return Err(format!("Could not install injected packages: {:?}", packages).into());
-        }
+        install_injected_packages(packages, &env, ctx.clone())?;
     }
 
     // Install arch-specific build dependencies
@@ -266,6 +256,59 @@ pub async fn build(
     Ok(())
 }
 
+fn install_injected_packages(
+    packages: &[&str],
+    env: &HashMap<String, String>,
+    ctx: Arc<Context>,
+) -> Result<(), Box<dyn Error>> {
+    log::info!("Installing injected packages: {:?}", packages);
+
+    // Separate .deb files from package names
+    let mut deb_files: Vec<String> = Vec::new();
+    let mut package_names: Vec<&str> = Vec::new();
+
+    for pkg in packages {
+        // Check if it's a .deb file path (ends with .deb and exists as a file)
+        let pkg_path = Path::new(pkg);
+        if pkg.ends_with(".deb") && pkg_path.exists() {
+            // Copy the .deb file into the build context
+            let dest_root = ctx.create_temp_dir()?;
+            let chroot_path = ctx.ensure_available(pkg_path, &dest_root)?;
+            log::debug!(
+                "Copied .deb file '{}' to chroot path '{}'",
+                pkg,
+                chroot_path.display()
+            );
+            deb_files.push(chroot_path.to_string_lossy().to_string());
+        } else {
+            package_names.push(pkg);
+        }
+    }
+
+    // Install .deb files
+    if !deb_files.is_empty() || !package_names.is_empty() {
+        log::info!("Installing .deb files: {:?}", deb_files);
+        let mut cmd = ctx.command("apt-get");
+        cmd.envs(env.clone())
+            .arg("-y")
+            .arg("--allow-downgrades")
+            .arg("install");
+        // Add the .deb file paths with ./ prefix for apt to recognize them as local files
+        for deb_path in &deb_files {
+            cmd.arg(format!("./{}", deb_path.trim_start_matches('/')));
+        }
+        if !package_names.is_empty() {
+            cmd.args(&package_names);
+        }
+        let status = cmd.status()?;
+        if !status.success() {
+            return Err(format!("Could not install injected packages: {:?}", deb_files).into());
+        }
+    }
+
+    Ok(())
+}
+
 fn dose3_explain_dependencies(
     package: &str,
     version: &str,