diff --git a/NEWS b/NEWS
index b2ccf3c6d..a61f1234f 100644
--- a/NEWS
+++ b/NEWS
@@ -20,6 +20,9 @@ Noteworthy changes in version 2.2.21 (unreleased)
   * gpgsm: Unless CRL checking is disabled lookup a missing issuer
     certificate using the certificate's authorityInfoAccess.  [#4898]
 
+  * gpgsm: Print the certificate's serial number also in decimal
+    notation.
+
   * gpgsm: Fix possible NULL-deref in messages of --gen-key.  [#4895]
 
   * scd: Support the CardOS 5 based D-Trust Card 3.1.
diff --git a/sm/certdump.c b/sm/certdump.c
index 7d09cdabd..c177cabcf 100644
--- a/sm/certdump.c
+++ b/sm/certdump.c
@@ -38,7 +38,7 @@
 
 #include "keydb.h"
 #include "../common/i18n.h"
-
+#include "../common/membuf.h"
 
 struct dn_array_s {
   char *key;
@@ -73,6 +73,85 @@ gpgsm_print_serial (estream_t fp, ksba_const_sexp_t sn)
 }
 
 
+/* Print the first element of an S-Expression in decimal notation
+ * assuming it is a non-negative integer. */
+void
+gpgsm_print_serial_decimal (estream_t fp, ksba_const_sexp_t sn)
+{
+  const char *p = (const char *)sn;
+  unsigned long n, i;
+  char *endp;
+  gcry_mpi_t a, r, ten;
+#if GCRYPT_VERSION_NUMBER >= 0x010900 /* >= 1.9.0 */
+  unsigned int dd;
+#else
+  unsigned char numbuf[10];
+#endif
+
+  if (!p)
+    es_fputs (_("none"), fp);
+  else if (*p != '(')
+    es_fputs ("[Internal error - not an S-expression]", fp);
+  else
+    {
+      p++;
+      n = strtoul (p, &endp, 10);
+      p = endp;
+      if (*p++ != ':')
+        es_fputs ("[Internal Error - invalid S-expression]", fp);
+      else if (gcry_mpi_scan (&a, GCRYMPI_FMT_USG, p, n, NULL))
+        es_fputs ("[Internal Error - can't convert to decimal]", fp);
+      else
+        {
+          membuf_t mb = MEMBUF_ZERO;
+          char *buf;
+          int c;
+
+          ten = gcry_mpi_set_ui (NULL, 10);
+          r = gcry_mpi_new (0);
+
+          do
+            {
+              gcry_mpi_div (a, r, a, ten, 0);
+#if GCRYPT_VERSION_NUMBER >= 0x010900 /* >= 1.9.0 */
+              gcry_mpi_get_ui (&dd, r);
+              put_membuf_printf (&mb, "%u", dd);
+#else
+              *numbuf = 0;  /* Need to clear because USB format prints
+                             * an empty string for a value of 0.  */
+              gcry_mpi_print (GCRYMPI_FMT_USG, numbuf, 10, NULL, r);
+              put_membuf_printf (&mb, "%u", (unsigned int)*numbuf);
+#endif
+            }
+          while (gcry_mpi_cmp_ui (a, 0));
+
+          /* Make sure we have at least an empty string, get it,
+           * reverse it, and print it. */
+          put_membuf (&mb, "", 1);
+          buf = get_membuf (&mb, NULL);
+          if (!buf)
+            es_fputs ("[Internal Error - out of core]", fp);
+          else
+            {
+              n = strlen (buf);
+              for (i=0; i < n/2; i++)
+                {
+                  c = buf[i];
+                  buf[i] = buf[n-1-i];
+                  buf[n-1-i] = c;
+                }
+              es_fputs (buf, fp);
+              xfree (buf);
+            }
+
+          gcry_mpi_release (r);
+          gcry_mpi_release (ten);
+          gcry_mpi_release (a);
+        }
+    }
+}
+
+
 /* Dump the serial number or any other simple S-expression. */
 void
 gpgsm_dump_serial (ksba_const_sexp_t sn)
diff --git a/sm/gpgsm.h b/sm/gpgsm.h
index 7738af57a..268c2d054 100644
--- a/sm/gpgsm.h
+++ b/sm/gpgsm.h
@@ -269,6 +269,7 @@ char *gpgsm_get_certid (ksba_cert_t cert);
 
 /*-- certdump.c --*/
 void gpgsm_print_serial (estream_t fp, ksba_const_sexp_t p);
+void gpgsm_print_serial_decimal (estream_t fp, ksba_const_sexp_t sn);
 void gpgsm_print_time (estream_t fp, ksba_isotime_t t);
 void gpgsm_print_name2 (FILE *fp, const char *string, int translate);
 void gpgsm_print_name (FILE *fp, const char *string);
diff --git a/sm/keylist.c b/sm/keylist.c
index 6b103e4b1..7961b66fd 100644
--- a/sm/keylist.c
+++ b/sm/keylist.c
@@ -738,8 +738,11 @@ list_cert_raw (ctrl_t ctrl, KEYDB_HANDLE hd,
   sexp = ksba_cert_get_serial (cert);
   es_fputs ("          S/N: ", fp);
   gpgsm_print_serial (fp, sexp);
-  ksba_free (sexp);
   es_putc ('\n', fp);
+  es_fputs ("        (dec): ", fp);
+  gpgsm_print_serial_decimal (fp, sexp);
+  es_putc ('\n', fp);
+  ksba_free (sexp);
 
   dn = ksba_cert_get_issuer (cert, 0);
   es_fputs ("       Issuer: ", fp);
@@ -1118,8 +1121,11 @@ list_cert_std (ctrl_t ctrl, ksba_cert_t cert, estream_t fp, int have_secret,
   sexp = ksba_cert_get_serial (cert);
   es_fputs ("          S/N: ", fp);
   gpgsm_print_serial (fp, sexp);
-  ksba_free (sexp);
   es_putc ('\n', fp);
+  es_fputs ("        (dec): ", fp);
+  gpgsm_print_serial_decimal (fp, sexp);
+  es_putc ('\n', fp);
+  ksba_free (sexp);
 
   dn = ksba_cert_get_issuer (cert, 0);
   es_fputs ("       Issuer: ", fp);