diff --git a/fuzzers/int_loop.mk b/fuzzers/int_loop.mk
index e7891582..a91b292d 100644
--- a/fuzzers/int_loop.mk
+++ b/fuzzers/int_loop.mk
@@ -1,5 +1,7 @@
 # WARNING: N cannot be reduced or -m will always fail
 N := 10
+# See int_loop_check.py
+CHECK_ARGS := --zero-entries --timeout-iters 100
 SPECIMENS := $(addprefix build/specimen_,$(shell seq -f '%03.0f' $(N)))
 SPECIMENS_OK := $(addsuffix /OK,$(SPECIMENS))
 # Individual fuzzer directory, such as ~/prjxray/fuzzers/010-lutinit
@@ -34,7 +36,7 @@ build/todo.txt: build/pips_int_l.txt maketodo.py
 # XXX: conider moving to script
 run:
 	$(MAKE) clean
-	MAKE="$(MAKE)" MAKEFLAGS="$(MAKEFLAGS)" QUICK=$(QUICK) $(FUZDIR)/../int_loop.sh
+	XRAY_DIR=${XRAY_DIR} MAKE="$(MAKE)" MAKEFLAGS="$(MAKEFLAGS)" QUICK=$(QUICK) $(XRAY_DIR)/fuzzers/int_loop.sh --check-args "$(CHECK_ARGS)"
 	touch run.ok
 
 clean:
diff --git a/fuzzers/int_loop.sh b/fuzzers/int_loop.sh
index 363eb6a3..9c968b3a 100755
--- a/fuzzers/int_loop.sh
+++ b/fuzzers/int_loop.sh
@@ -1,4 +1,31 @@
 #!/usr/bin/env bash
+
+usage() {
+    echo "Run makefile until termination condition"
+    echo "usage: int_loop.sh [args]"
+    echo "--check-args <args>         int_loop_check.py args"
+}
+
+check_args=
+while [[ $# -gt 0 ]]; do
+    case "$1" in
+    --check-args)
+        check_args=$2
+        shift
+        shift
+        ;;
+    -h|--help)
+        usage
+        exit 0
+        ;;
+    *)
+        echo "Unrecognized argument"
+        usage
+        exit 1
+        ;;
+    esac
+done
+
 set -ex
 MAKE=${MAKE:-make}
 MAKEFLAGS=${MAKEFLAGS:-}
@@ -8,8 +35,7 @@ mkdir -p todo;
 while true; do
     ${MAKE} ${MAKEFLAGS} cleanprj;
     ${MAKE} ${MAKEFLAGS} build/todo.txt || exit 1;
-    echo "Remaining: " $(wc -l build/todo_all.txt)
-    if [ \! -s build/todo.txt ] ; then
+    if python3 ${XRAY_DIR}/fuzzers/int_loop_check.py $check_args ; then
         break
     fi
 
diff --git a/fuzzers/int_loop_check.py b/fuzzers/int_loop_check.py
new file mode 100644
index 00000000..25d66f95
--- /dev/null
+++ b/fuzzers/int_loop_check.py
@@ -0,0 +1,146 @@
+#!/usr/bin/env python3
+
+import sys, re
+import os
+import glob
+import hashlib
+
+
+# len(txt.split("\n"))) is off by 1
+def wc(fn):
+    i = 0
+    with open(fn) as f:
+        for i, _l in enumerate(f, 1):
+            pass
+    return i
+
+
+def bytehex(x):
+    return ''.join('{:02x}'.format(x) for x in x)
+
+
+def calc_stable_iters(todo_dir, max_iter):
+    m5s = []
+    wcs = []
+    m5_last = None
+    stablen = 0
+    for fni in range(1, max_iter + 1, 1):
+        fn = "%s/%u_all.txt" % (todo_dir, fni)
+        txt = open(fn, "r").read()
+        m5 = hashlib.md5(txt.encode("ascii")).hexdigest()
+
+        m5s.append(m5)
+        wc_this = wc(fn)
+        wcs.append(wc_this)
+
+        if m5_last == m5:
+            stablen += 1
+        else:
+            stablen = 1
+
+        print(
+            "% 4u %s % 6u lines % 6u stable" %
+            (fni, m5[0:8], wc_this, stablen))
+
+        m5_last = m5
+
+    return stablen
+
+
+def run(
+        todo_dir,
+        min_iters=None,
+        stable_iters=None,
+        timeout_iters=None,
+        zero_entries=None,
+        verbose=False):
+    timeout_fn = "%s/timeout" % todo_dir
+    # make clean removes todo dir, but helps debugging
+    if os.path.exists(timeout_fn):
+        print("WARNING: removing %s" % timeout_fn)
+        os.remove(timeout_fn)
+
+    alls = glob.glob("%s/*_all.txt" % todo_dir)
+    max_iter = 0
+    for fn in alls:
+        n = int(re.match(r".*/([0-9]*)_all.txt", fn).group(1))
+        max_iter = max(max_iter, n)
+
+    if max_iter == 0:
+        print("Incomplete: no iters")
+        sys.exit(1)
+
+    verbose and print("Max iter: %u, need: %s" % (max_iter, min_iters))
+
+    fn = "%s/%u_all.txt" % (todo_dir, max_iter)
+    txt = open(fn, "r").read()
+    nbytes = len(txt)
+
+    stablen = calc_stable_iters(todo_dir, max_iter)
+
+    if min_iters is not None and max_iter < min_iters:
+        print("Incomplete: not enough iters")
+        sys.exit(1)
+
+    if timeout_iters is not None and max_iter > timeout_iters:
+        print("ERROR: timeout (max %u, got %u)" % (timeout_iters, max_iter))
+        with open(timeout_fn, "w") as _f:
+            pass
+        sys.exit(1)
+
+    if zero_entries and nbytes:
+        print("%s: %u bytes, %s lines" % (fn, nbytes, wc(fn)))
+        print("Incomplete: need zero entries")
+        sys.exit(1)
+
+    if stable_iters:
+        if stablen < stable_iters:
+            print(
+                "Incomplete: insufficient stable iters (got %s, need %s)" %
+                (stablen, stable_iters))
+            sys.exit(1)
+
+    print("Complete!")
+    sys.exit(0)
+
+
+def main():
+    import argparse
+
+    parser = argparse.ArgumentParser(
+        description=
+        "Check int_loop completion. Exits 0 on done, 1 if more loops are needed"
+    )
+
+    parser.add_argument('--verbose', action='store_true', help='')
+    parser.add_argument('--todo-dir', default="todo", help='')
+    parser.add_argument(
+        '--min-iters', default=None, help='Minimum total number of iterations')
+    parser.add_argument(
+        '--stable-iters',
+        default=None,
+        help='Number of iterations without any change')
+    parser.add_argument(
+        '--timeout-iters',
+        default=None,
+        help='Max number of entries before creating todo/timeout')
+    parser.add_argument(
+        '--zero-entries',
+        action="store_true",
+        help='Must be no unsolved entries in latest')
+    args = parser.parse_args()
+
+    def zint(x):
+        return None if x is None else int(x)
+
+    run(
+        args.todo_dir,
+        zint(args.min_iters),
+        zint(args.stable_iters),
+        zint(args.timeout_iters),
+        args.zero_entries,
+        verbose=args.verbose)
+
+
+if __name__ == '__main__':
+    main()