diff --git a/src/librustc_mir/interpret/memory.rs b/src/librustc_mir/interpret/memory.rs
index e251d7ec2bbf..b62add8a559b 100644
--- a/src/librustc_mir/interpret/memory.rs
+++ b/src/librustc_mir/interpret/memory.rs
@@ -799,6 +799,7 @@ pub fn write_scalar(
         signed: bool,
     ) -> EvalResult<'tcx> {
         let endianness = self.endianness();
+        self.check_align(ptr, ptr_align)?;
 
         let val = match val {
             ScalarMaybeUndef::Scalar(scalar) => scalar,