diff --git a/asm/nasm.c b/asm/nasm.c
index 69a3db55..c5d9aff1 100644
--- a/asm/nasm.c
+++ b/asm/nasm.c
@@ -105,7 +105,7 @@ bool tasm_compatible_mode = false;
 enum pass_type _pass_type;
 const char * const _pass_types[] =
 {
-    "init", "first", "optimize", "stabilize", "final"
+    "init", "preproc-only", "first", "optimize", "stabilize", "final"
 };
 int64_t _passn;
 int globalrel = 0;
diff --git a/include/nasm.h b/include/nasm.h
index 616ffb37..efeb6190 100644
--- a/include/nasm.h
+++ b/include/nasm.h
@@ -1280,6 +1280,8 @@ struct optimization {
 
 /*
  * Various types of compiler passes we may execute.
+ * If these are changed, you need to also change _pass_types[]
+ * in asm/nasm.c.
  */
 enum pass_type {
     PASS_INIT,            /* Initialization, not doing anything yet */