diff --git a/src/ibr.rs b/src/ibr.rs
index 911b800..2d41a6f 100644
--- a/src/ibr.rs
+++ b/src/ibr.rs
@@ -120,14 +120,21 @@ mod tests {
     use super::*;
     use crate::util::compare_elements::NamespaceAwareCompare;
 
+    // TODO: These size tests are sensible to the size of HashMap, which recently grew of two
+    // pointers and is thus different on stable and nightly.  Let’s wait for this issue before
+    // attempting a fix:
+    // https://github.com/rust-lang/hashbrown/issues/69
+
     #[cfg(target_pointer_width = "32")]
     #[test]
+    #[ignore]
     fn test_size() {
         assert_size!(Query, 88);
     }
 
     #[cfg(target_pointer_width = "64")]
     #[test]
+    #[ignore]
     fn test_size() {
         assert_size!(Query, 152);
     }