diff --git a/cmds/installd/otapreopt.cpp b/cmds/installd/otapreopt.cpp
index ff838ce..9a3fb70 100644
--- a/cmds/installd/otapreopt.cpp
+++ b/cmds/installd/otapreopt.cpp
@@ -734,6 +734,10 @@
     }
 
     static const char* ParseNull(const char* arg) {
+        // b/38186355. Revert soon.
+        if (strcmp(arg, "!null") == 0) {
+            return nullptr;
+        }
         return (strcmp(arg, "!") == 0) ? nullptr : arg;
     }