diff --git a/src/test/run-pass/intrinsic-alignment.rs b/src/test/run-pass/intrinsic-alignment.rs
index 197b92ba6352..ad9f8459eb79 100644
--- a/src/test/run-pass/intrinsic-alignment.rs
+++ b/src/test/run-pass/intrinsic-alignment.rs
@@ -51,6 +51,15 @@ mod m {
             assert_eq!(::rusti::min_align_of::<u64>(), 8u);
         }
     }
+
+    #[main]
+    #[cfg(target_arch = "x86_64")]
+    pub fn main() {
+        unsafe {
+            assert_eq!(::rusti::pref_align_of::<u64>(), 8u);
+            assert_eq!(::rusti::min_align_of::<u64>(), 8u);
+        }
+    }
 }
 
 #[cfg(target_os = "android")]
diff --git a/src/test/run-pass/rec-align-u64.rs b/src/test/run-pass/rec-align-u64.rs
index ada012fc2f50..88295208672b 100644
--- a/src/test/run-pass/rec-align-u64.rs
+++ b/src/test/run-pass/rec-align-u64.rs
@@ -61,6 +61,12 @@ mod m {
         pub fn align() -> uint { 8u }
         pub fn size() -> uint { 16u }
     }
+
+    #[cfg(target_arch = "x86_64")]
+    pub mod m {
+        pub fn align() -> uint { 8u }
+        pub fn size() -> uint { 16u }
+    }
 }
 
 #[cfg(target_os = "android")]