diff --git a/src/lib.rs b/src/lib.rs
index c147a39..5f2f296 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -39,7 +39,7 @@
 use clap::{App, AppSettings, Arg, SubCommand};
 use cross::{pkg_config_path, run_configure, run_pkg_config};
 use device::{netaddr, netls, scp_to_device, ssh, start_emulator, stop_emulator};
-use sdk::{clang_linker_path, sysroot_path};
+use sdk::{clang_linker_path, sysroot_path, target_gen_dir};
 pub use sdk::TargetOptions;
 use std::fs;
 use std::path::PathBuf;
@@ -246,7 +246,7 @@
 /// use fargo::{run_cargo, TargetOptions};
 ///
 /// let target_options = TargetOptions::new(true, None);
-/// run_cargo(false, true, false, &["--help"], &target_options, None);
+/// run_cargo(false, true, false, &["--help"], &target_options, None, None);
 ///
 /// ```
 pub fn run_cargo(
@@ -322,6 +322,7 @@
         .env("PKG_CONFIG_ALLOW_CROSS", "1")
         .env("PKG_CONFIG_PATH", "")
         .env("PKG_CONFIG_LIBDIR", pkg_path)
+        .env("FUCHSIA_GEN_ROOT", target_gen_dir(target_options)?)
         .args(args)
         .args(target_args);
 
diff --git a/src/sdk.rs b/src/sdk.rs
index b731f39..db4eb9a 100644
--- a/src/sdk.rs
+++ b/src/sdk.rs
@@ -80,16 +80,18 @@
     possible_target_out_dir(&fuchsia_root, options)
 }
 
+pub fn target_gen_dir(options: &TargetOptions) -> Result<PathBuf> {
+    let target_out_dir = target_out_dir(options)?;
+    Ok(target_out_dir.join("gen"))
+}
+
 pub fn strip_tool_path(target_options: &TargetOptions) -> Result<PathBuf> {
     Ok(toolchain_path(target_options)?.join("bin/strip"))
 }
 
 pub fn sysroot_path(options: &TargetOptions) -> Result<PathBuf> {
-    let zircon_name = if options.target_cpu == "x86-64" {
-        "build-user-x86-64"
-    } else {
-        "build-user-arm64"
-    };
+    let zircon_name =
+        if options.target_cpu == "x86-64" { "build-user-x86-64" } else { "build-user-arm64" };
     Ok(fuchsia_root(&options)?.join("out").join("build-zircon").join(zircon_name).join("sysroot"))
 }