diff --git a/src/librustc_back/target/asmjs_unknown_emscripten.rs b/src/librustc_back/target/asmjs_unknown_emscripten.rs
index d86a9b09327..51befa78ed3 100644
--- a/src/librustc_back/target/asmjs_unknown_emscripten.rs
+++ b/src/librustc_back/target/asmjs_unknown_emscripten.rs
@@ -32,6 +32,7 @@ pub fn target() -> Result<Target, String> {
         target_os: "emscripten".to_string(),
         target_env: "".to_string(),
         target_vendor: "unknown".to_string(),
+        target_family: Some("unix".to_string()),
         data_layout: "e-p:32:32-i64:64-v128:32:128-n32-S128".to_string(),
         arch: "asmjs".to_string(),
         options: opts,
diff --git a/src/librustc_back/target/wasm32_unknown_emscripten.rs b/src/librustc_back/target/wasm32_unknown_emscripten.rs
index 77ab4fcae70..574dbe980f1 100644
--- a/src/librustc_back/target/wasm32_unknown_emscripten.rs
+++ b/src/librustc_back/target/wasm32_unknown_emscripten.rs
@@ -35,6 +35,7 @@ pub fn target() -> Result<Target, String> {
         target_os: "emscripten".to_string(),
         target_env: "".to_string(),
         target_vendor: "unknown".to_string(),
+        target_family: Some("unix".to_string()),
         data_layout: "e-p:32:32-i64:64-v128:32:128-n32-S128".to_string(),
         arch: "wasm32".to_string(),
         options: opts,