diff --git a/bfd/coffcode.h b/bfd/coffcode.h
index 7439fca676..5c9722a15e 100644
--- a/bfd/coffcode.h
+++ b/bfd/coffcode.h
@@ -360,6 +360,10 @@ CODE_FRAGMENT
 #include "coffswap.h"
 #endif
 
+#ifdef COFF_WITH_PE_BIGOBJ
+extern const bfd_target TARGET_SYM_BIG;
+#endif
+
 #define STRING_SIZE_SIZE 4
 
 #define DOT_DEBUG	".debug"
@@ -3154,6 +3158,16 @@ coff_compute_section_file_positions (bfd * abfd)
 
   if (target_index >= bfd_coff_max_nscns (abfd))
     {
+#ifdef COFF_WITH_PE_BIGOBJ
+      if (abfd->xvec != &TARGET_SYM_BIG)
+	{
+	  /* Regular PE/COFF uses 16-bit section numbers in symbols.
+	     Promote oversized objects to the matching bigobj target
+	     before any headers or symbols are finalized.  */
+	  abfd->xvec = &TARGET_SYM_BIG;
+	  return coff_compute_section_file_positions (abfd);
+	}
+#endif
       bfd_set_error (bfd_error_file_too_big);
       _bfd_error_handler
 	/* xgettext:c-format */
diff --git a/gas/testsuite/gas/pe/big-obj-auto.d b/gas/testsuite/gas/pe/big-obj-auto.d
new file mode 100644
index 0000000000..9538ed4c67
--- /dev/null
+++ b/gas/testsuite/gas/pe/big-obj-auto.d
@@ -0,0 +1,9 @@
+#objdump: -h
+#name: PE big obj auto-promotion
+
+.*: *file format pe-bigobj-.*
+
+Sections:
+#...
+5000. \.data\$a49999  .*
+                  CONTENTS, ALLOC, LOAD, DATA
diff --git a/gas/testsuite/gas/pe/big-obj-auto.s b/gas/testsuite/gas/pe/big-obj-auto.s
new file mode 100644
index 0000000000..dbf2585e81
--- /dev/null
+++ b/gas/testsuite/gas/pe/big-obj-auto.s
@@ -0,0 +1,16 @@
+	.file "big-obj-auto.s"
+
+	.irp n,0,1,2,3,4
+	.irp m,0,1,2,3,4,5,6,7,8,9
+	.irp c,0,1,2,3,4,5,6,7,8,9
+	.irp d,0,1,2,3,4,5,6,7,8,9
+	.irp u,0,1,2,3,4,5,6,7,8,9
+	.globl a\n\m\c\d\u
+	.section .data$a\n\m\c\d\u,"w"
+a\n\m\c\d\u :
+	.byte 1
+	.endr
+	.endr
+	.endr
+	.endr
+	.endr
diff --git a/gas/testsuite/gas/pe/pe.exp b/gas/testsuite/gas/pe/pe.exp
index e25de3cfa9..092ab4b335 100644
--- a/gas/testsuite/gas/pe/pe.exp
+++ b/gas/testsuite/gas/pe/pe.exp
@@ -70,4 +70,5 @@ if {[istarget "aarch64-*-pe*"] || [istarget "aarch64-*-mingw*"]} {
 
 if ([istarget "*-*-mingw*"]) then {
 	run_dump_test "big-obj"
+	run_dump_test "big-obj-auto"
 }