diff --git a/scripts/reduce-predicate.sh b/scripts/reduce-predicate.sh
new file mode 100755
index 0000000..eb69948
--- /dev/null
+++ b/scripts/reduce-predicate.sh
@@ -0,0 +1,20 @@
+#!/bin/bash
+
+timeout 1 wasmtime run --disable-cache $1
+if [ $? -ne 0 ]; then
+    echo bad: initial run crashes too
+    exit 1
+fi
+target/release/waffle-util roundtrip -i $1 -o o.wasm
+if [ $? -ne 0 ]; then
+    echo bad: roundtrip
+    exit 1
+fi
+wasmtime run --disable-cache o.wasm
+if [ $? -ne 0 ]; then
+    echo ok: still crashes
+    exit 0
+else
+    echo bad: no longer crashes
+    exit 1
+fi