diff --git a/src/librustc_back/target/asmjs_unknown_emscripten.rs b/src/librustc_back/target/asmjs_unknown_emscripten.rs
index d86a9b093272e..98a9e343d0044 100644
--- a/src/librustc_back/target/asmjs_unknown_emscripten.rs
+++ b/src/librustc_back/target/asmjs_unknown_emscripten.rs
@@ -23,6 +23,7 @@ pub fn target() -> Result<Target, String> {
         obj_is_bitcode: true,
         max_atomic_width: Some(32),
         post_link_args: vec!["-s".to_string(), "ERROR_ON_UNDEFINED_SYMBOLS=1".to_string()],
+        target_family: Some("unix".to_string()),
         .. Default::default()
     };
     Ok(Target {
diff --git a/src/librustc_back/target/wasm32_unknown_emscripten.rs b/src/librustc_back/target/wasm32_unknown_emscripten.rs
index 77ab4fcae7008..fec269074da8b 100644
--- a/src/librustc_back/target/wasm32_unknown_emscripten.rs
+++ b/src/librustc_back/target/wasm32_unknown_emscripten.rs
@@ -26,6 +26,7 @@ pub fn target() -> Result<Target, String> {
         max_atomic_width: Some(32),
         post_link_args: vec!["-s".to_string(), "BINARYEN=1".to_string(),
                              "-s".to_string(), "ERROR_ON_UNDEFINED_SYMBOLS=1".to_string()],
+        target_family: Some("unix".to_string()),
         .. Default::default()
     };
     Ok(Target {