diff --git a/format/testdata/fuzz/FuzzFormatExpansionRoundTrip/2e57951e124dc12b b/format/testdata/fuzz/FuzzFormatExpansionRoundTrip/2e57951e124dc12b
new file mode 100644
index 0000000..ca0d534
--- /dev/null
+++ b/format/testdata/fuzz/FuzzFormatExpansionRoundTrip/2e57951e124dc12b
@@ -0,0 +1,2 @@
+go test fuzz v1
+string("#define M() \\\n\tADD $1, R0 \\\n\tSUB $2, R1\nM()\n")
diff --git a/format/testdata/fuzz/FuzzFormatExpansionRoundTrip/fab61ade833f43b6 b/format/testdata/fuzz/FuzzFormatExpansionRoundTrip/fab61ade833f43b6
new file mode 100644
index 0000000..914cedc
--- /dev/null
+++ b/format/testdata/fuzz/FuzzFormatExpansionRoundTrip/fab61ade833f43b6
@@ -0,0 +1,2 @@
+go test fuzz v1
+string("#define M (BX)\nMOVL M, AX\n")