diff --git a/tests/vectors/numeric-leaves/README.md b/tests/vectors/numeric-leaves/README.md
index e7ecb070..3007204e 100644
--- a/tests/vectors/numeric-leaves/README.md
+++ b/tests/vectors/numeric-leaves/README.md
@@ -12,3 +12,5 @@ A document with one slot, `[value]`, whose slot is a C# `int`, `long`, `float` o
   the double it read (a float32 widened), and empty when refused. Every value is fed to every leaf.
 - `writes.msgpack`: an array of `[leaf, text, bytes]`. `text` is a decimal for an integer leaf and the double's IEEE
   bits in hex for a float leaf; `bytes` (bin) is the one-slot record the reference writes for that value.
+- `float32-nan.msgpack`: an array of `[payload, bytes]`. `payload` (bin) is a one-slot `float` record holding an infinity
+  or a NaN; `bytes` (bin) is what the reference writes after reading it. It keeps every bit, a signalling NaN's included.
diff --git a/tests/vectors/numeric-leaves/float32-nan.msgpack b/tests/vectors/numeric-leaves/float32-nan.msgpack
new file mode 100644
index 00000000..6c65acba
Binary files /dev/null and b/tests/vectors/numeric-leaves/float32-nan.msgpack differ
diff --git a/tests/vectors/numeric-leaves/reads.msgpack b/tests/vectors/numeric-leaves/reads.msgpack
index 51991ff2..36f7f061 100644
Binary files a/tests/vectors/numeric-leaves/reads.msgpack and b/tests/vectors/numeric-leaves/reads.msgpack differ