diff --git a/doc/dev/howto/tests.md b/doc/dev/howto/tests.md
index 2cb03451a8..a2d924e84e 100644
--- a/doc/dev/howto/tests.md
+++ b/doc/dev/howto/tests.md
@@ -129,7 +129,7 @@ ngl-serialize pynodegl_utils.examples.misc fibo /tmp/fibo.ngl
 
 # Count the number of mallocs (the last lines will contain something like
 # MEMCOUNT: 858)
-NGL_MEM_ALLOC_FAIL=count ngl-render -t 0:30:60 /tmp/fibo.ngl
+NGL_MEM_ALLOC_FAIL=count ngl-render -t 0:30:60 -i /tmp/fibo.ngl
 
 # Make them fail one by one
 for i in $(seq 0 858); do