diff --git a/asm/assemble.c b/asm/assemble.c
index 632641e0b..29ac92291 100644
--- a/asm/assemble.c
+++ b/asm/assemble.c
@@ -872,6 +872,17 @@ static void out_eops(struct out_data *data, const extop *e)
 /* This is totally just a wild guess what is reasonable... */
 #define INCBIN_MAX_BUF (ZERO_BUF_SIZE * 16)
 
+static void
+list_add_template_info(const insn *ins, const struct itemplate *temp)
+{
+    char *buf;
+    (void)ins;
+
+    buf = nasm_asprintf(" ;;; matched insns.xda:%u", temp->xdaline);
+    lfmt->line(LIST_INFO, -1, buf);
+    nasm_free(buf);
+}
+
 static int64_t assemble(insn *instruction)
 {
     struct out_data data;
@@ -1012,6 +1023,9 @@ static int64_t assemble(insn *instruction)
 
         if (m >= MOK_GOOD) {
             /* Matches! */
+            if (list_option('X'))
+                list_add_template_info(instruction, temp);
+
             if (unlikely(itemp_has(temp, IF_OBSOLETE))) {
                 errflags warning;
                 const char *whathappened;
diff --git a/asm/listing.h b/asm/listing.h
index 44b40fb58..6fa09db15 100644
--- a/asm/listing.h
+++ b/asm/listing.h
@@ -136,10 +136,15 @@ static inline const_func uint64_t list_option_mask_val(unsigned char x)
 
 static inline const_func uint64_t list_option_mask(unsigned char x)
 {
-    if (x == '+')
-        return ~(list_option_mask_val('w') | 3);
-    else
+    if (x == '+') {
+        const char *p = "bdefFmps";
+        uint64_t v = 0;
+        while (*p)
+            v |= list_option_mask_val(*p++);
+        return v;
+    } else {
         return list_option_mask_val(x);
+    }
 }
 
 /* Return true if the listing engine is active and a certain option is set. */
diff --git a/asm/nasm.c b/asm/nasm.c
index 128e5b721..1daea49d9 100644
--- a/asm/nasm.c
+++ b/asm/nasm.c
@@ -1932,6 +1932,7 @@ static void help(FILE *out, const char *what)
     }
     if (help_is(with, 'L')) {
         fputs(
+            "                -L flags for general usage:\n"
             "       -Lb         show builtin macro packages (standard and %use)\n"
             "       -Ld         show byte and repeat counts in decimal, not hex\n"
             "       -Le         show the preprocessed output\n"
@@ -1940,8 +1941,10 @@ static void help(FILE *out, const char *what)
             "       -Lm         show multi-line macro calls with expanded parameters\n"
             "       -Lp         output a list file every pass, in case of errors\n"
             "       -Ls         show all single-line macro definitions\n"
+            "       -L+         enable all of the above listing options (very verbose!)\n"
+            "                -L flags intended for debugging NASM:\n"
             "       -Lw         flush the output after every line (very slow!)\n"
-            "       -L+         enable all listing options except -Lw (very verbose!)\n"
+            "       -LX         list instruction pattern line numbers from insns.xda\n"
             , out);
     }
     if (help_optor(with, 'O')) {
diff --git a/include/nasm.h b/include/nasm.h
index 1e8aee026..7ea54b7f9 100644
--- a/include/nasm.h
+++ b/include/nasm.h
@@ -526,6 +526,7 @@ static inline char *nasm_skip_identifier(const char *str)
 enum {
     LIST_READ,
     LIST_MACRO,
+    LIST_INFO,
     LIST_INCLUDE,
     LIST_INCBIN,
     LIST_TIMES