diff --git a/common/iobuf.c b/common/iobuf.c
index bf5977843..02c9b491c 100644
--- a/common/iobuf.c
+++ b/common/iobuf.c
@@ -59,9 +59,7 @@
 
 /*-- Begin configurable part.  --*/
 
-/* The size of the internal buffers.
-   NOTE: If you change this value you MUST also adjust the regression
-   test "armored_key_8192" in armor.test! */
+/* The standard size of the internal buffers.  */
 #define DEFAULT_IOBUF_BUFFER_SIZE  (64*1024)
 
 /* To avoid a potential DoS with compression packets we better limit
diff --git a/doc/gpg.texi b/doc/gpg.texi
index 1e6ea595f..83b234e47 100644
--- a/doc/gpg.texi
+++ b/doc/gpg.texi
@@ -2859,6 +2859,12 @@ Set all useful debugging flags.
 Set stdout into line buffered mode.  This option is only honored when
 given on the command line.
 
+@item --debug-set-iobuf-size @var{n}
+@opindex debug-iolbf
+Change the buffer size of the IOBUFs to @var{n} kilobyte.  Using 0
+prints the current size.  Note well: This is a maintainer only option
+and may thus be changed or removed at any time without notice.
+
 @item --faked-system-time @var{epoch}
 @opindex faked-system-time
 This option is only useful for testing; it sets the system time back or
diff --git a/g10/gpg.c b/g10/gpg.c
index 283de2038..cbac967d8 100644
--- a/g10/gpg.c
+++ b/g10/gpg.c
@@ -223,6 +223,7 @@ enum cmd_and_opt_values
     oDebugLevel,
     oDebugAll,
     oDebugIOLBF,
+    oDebugSetIobufSize,
     oStatusFD,
     oStatusFile,
     oAttributeFD,
@@ -642,6 +643,7 @@ static ARGPARSE_OPTS opts[] = {
   ARGPARSE_s_s (oDebugLevel, "debug-level", "@"),
   ARGPARSE_s_n (oDebugAll, "debug-all", "@"),
   ARGPARSE_s_n (oDebugIOLBF, "debug-iolbf", "@"),
+  ARGPARSE_s_u (oDebugSetIobufSize, "debug-set-iobuf-size", "@"),
   ARGPARSE_s_i (oStatusFD, "status-fd", "@"),
   ARGPARSE_s_s (oStatusFile, "status-file", "@"),
   ARGPARSE_s_i (oAttributeFD, "attribute-fd", "@"),
@@ -956,6 +958,8 @@ int g10_errors_seen = 0;
 
 static int utf8_strings = 0;
 static int maybe_setuid = 1;
+static unsigned int opt_set_iobuf_size;
+static unsigned int opt_set_iobuf_size_used;
 
 static char *build_list( const char *text, char letter,
 			 const char *(*mapf)(int), int (*chkf)(int) );
@@ -1276,6 +1280,10 @@ set_debug (const char *level)
 
   if (opt.debug)
     parse_debug_flag (NULL, &opt.debug, debug_flags);
+
+  if (opt_set_iobuf_size || opt_set_iobuf_size_used)
+    log_debug ("iobuf buffer size is %uk\n",
+               iobuf_set_buffer_size (opt_set_iobuf_size));
 }
 
 
@@ -2742,6 +2750,11 @@ main (int argc, char **argv)
 
           case oDebugIOLBF: break; /* Already set in pre-parse step.  */
 
+          case oDebugSetIobufSize:
+            opt_set_iobuf_size = pargs.r.ret_ulong;
+            opt_set_iobuf_size_used = 1;
+            break;
+
 	  case oStatusFD:
             set_status_fd ( translate_sys2libc_fd_int (pargs.r.ret_int, 1) );
             break;
diff --git a/tests/openpgp/armor.scm b/tests/openpgp/armor.scm
index 3c117dd10..a1b0aa938 100755
--- a/tests/openpgp/armor.scm
+++ b/tests/openpgp/armor.scm
@@ -191,7 +191,7 @@ nW1ff9rt1YcTH9LiiE4EGBECAAYFAjnKLe0AEgkQ3uyMCd5BWw4HZUdQRwABAZeBAKDsa7tc
 (info "Checking armored_key_8192")
 (pipe:do
  (pipe:echo armored_key_8192)
- (pipe:gpg '(--import)))
+ (pipe:gpg '(--debug-set-iobuf-size=8 --import)))
 
 (define nopad_armored_msg "-----BEGIN PGP MESSAGE-----
 Version: GnuPG v1.4.11-svn5139 (GNU/Linux)
@@ -758,10 +758,10 @@ wg7Md81a5RI3F2FG8747t9gX
 (info "Importing alpha_seckey")
 (pipe:do
  (pipe:echo alpha_seckey)
- (pipe:gpg '(--import)))
+ (pipe:gpg '(--debug-set-iobuf-size=8 --import)))
 
 (info "Checking for bug #1179")
 (tr:do
  (tr:pipe-do
   (pipe:echo nopad_armored_msg)
-  (pipe:gpg '(--decrypt))))
+  (pipe:gpg '(--debug-set-iobuf-size=8 --decrypt))))