diff --git a/definitions/boot.def b/definitions/boot.def
index 22edf96e1..61a7b7be0 100644
--- a/definitions/boot.def
+++ b/definitions/boot.def
@@ -52,6 +52,9 @@ transient unitsFactor=1 : hidden;
 transient unitsBias=0 : hidden;
 constant globalDomain = "g";
 transient timeRangeIndicatorFromStepRange=-1 : hidden;
+# Format specifiers for converting a number (float or int) into a string
+transient formatForDoubles = "%g"  : no_copy,hidden;
+transient formatForLongs   = "%ld" : no_copy,hidden;
 
 # ECC-868
 transient produceLargeConstantFields = 0 : hidden;
diff --git a/src/grib_accessor_class_double.cc b/src/grib_accessor_class_double.cc
index e1888ed0c..3f635720c 100644
--- a/src/grib_accessor_class_double.cc
+++ b/src/grib_accessor_class_double.cc
@@ -8,10 +8,6 @@
  * virtue of its status as an intergovernmental organisation nor does it submit to any jurisdiction.
  */
 
-/************************************************
- *  Enrico Fucile
- ***********************************************/
-
 #include "grib_api_internal.h"
 /*
    This is used by make_class.pl
@@ -115,13 +111,18 @@ static int unpack_string(grib_accessor* a, char* v, size_t* len)
     double val = 0;
     size_t l   = 1;
     char repres[1024];
+    char format[32] = "%g";
+    grib_handle* h = grib_handle_of_accessor(a);
 
     grib_unpack_double(a, &val, &l);
 
-    if ((val == GRIB_MISSING_DOUBLE) && ((a->flags & GRIB_ACCESSOR_FLAG_CAN_BE_MISSING) != 0))
+    if ((val == GRIB_MISSING_DOUBLE) && ((a->flags & GRIB_ACCESSOR_FLAG_CAN_BE_MISSING) != 0)) {
         snprintf(repres, sizeof(repres), "MISSING");
-    else
-        snprintf(repres, sizeof(repres), "%g", val);
+    } else {
+        size_t size = sizeof(format);
+        grib_get_string(h, "formatForDoubles", format, &size);
+        snprintf(repres, sizeof(repres), format, val);
+    }
 
     l = strlen(repres) + 1;
 
diff --git a/src/grib_accessor_class_long.cc b/src/grib_accessor_class_long.cc
index c939189a5..1f97a539e 100644
--- a/src/grib_accessor_class_long.cc
+++ b/src/grib_accessor_class_long.cc
@@ -120,6 +120,8 @@ static int unpack_string(grib_accessor* a, char* v, size_t* len)
     long val = 0;
     size_t l = 1;
     char repres[1024];
+    char format[32] = "%ld";
+    grib_handle* h = grib_handle_of_accessor(a);
 
     err = grib_unpack_long(a, &val, &l);
     /* TODO: We should catch all errors but in this case the test ERA_Gen.sh will fail
@@ -127,10 +129,13 @@ static int unpack_string(grib_accessor* a, char* v, size_t* len)
     /* if (err) return err; */
     (void)err;
 
-    if ((val == GRIB_MISSING_LONG) && ((a->flags & GRIB_ACCESSOR_FLAG_CAN_BE_MISSING) != 0))
+    if ((val == GRIB_MISSING_LONG) && ((a->flags & GRIB_ACCESSOR_FLAG_CAN_BE_MISSING) != 0)) {
         snprintf(repres, sizeof(repres), "MISSING");
-    else
-        snprintf(repres, sizeof(repres), "%ld", val);
+    } else {
+        size_t size = sizeof(format);
+        grib_get_string(h, "formatForLongs", format, &size);
+        snprintf(repres, sizeof(repres), format, val);
+    }
 
     l = strlen(repres) + 1;
 
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index ad9f7c408..172101ad9 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -236,6 +236,7 @@ if( HAVE_BUILD_TOOLS )
         grib_set_bytes
         grib_set_force
         bufr_ecc-556
+        codes_ecc-1698
         gts_get
         gts_ls
         gts_count
diff --git a/tests/codes_ecc-1698.sh b/tests/codes_ecc-1698.sh
new file mode 100755
index 000000000..d7e0d49ec
--- /dev/null
+++ b/tests/codes_ecc-1698.sh
@@ -0,0 +1,45 @@
+#!/bin/sh
+# (C) Copyright 2005- ECMWF.
+#
+# This software is licensed under the terms of the Apache Licence Version 2.0
+# which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
+# 
+# In applying this licence, ECMWF does not waive the privileges and immunities granted to it by
+# virtue of its status as an intergovernmental organisation nor does it submit to any jurisdiction.
+#
+
+. ./include.ctest.sh
+
+REDIRECT=/dev/null
+
+label="codes_ecc-1698_test"
+tempGrib=temp.$label.grib
+tempBufr=temp.$label.bufr
+tempFilt=temp.$label.filt
+tempLog=temp.$label.log
+tempRef=temp.$label.ref
+
+sample_grib2=$ECCODES_SAMPLES_PATH/GRIB2.tmpl
+sample_bufr4=$ECCODES_SAMPLES_PATH/BUFR4.tmpl
+
+# Double to string
+# ------------------
+infile=$sample_grib2
+result=$(${tools_dir}/grib_get -p maximum:s $infile)
+[ "$result" = "1" ]
+result=$(${tools_dir}/grib_get -s formatForDoubles=%e -p maximum:s $infile)
+[ "$result" = "1.000000e+00" ]
+
+infile=${data_dir}/sample.grib2
+result=$(${tools_dir}/grib_get -s formatForDoubles=%e -p minimum:s $infile)
+[ "$result" = "2.704668e+02" ]
+
+
+# Integer to string
+# ------------------
+infile=${data_dir}/sample.grib2
+result=$(${tools_dir}/grib_get -s formatForLongs=%lX -p year:s $infile)
+[ "$result" = "7D8" ]
+
+
+rm -f $tempGrib $tempBufr $tempFilt $tempLog $tempRef