diff --git a/.gitignore b/.gitignore
index ac8d17c..68b6fcf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -33,6 +33,7 @@
 /tests/test_set_serializer
 /tests/test_compare
 /tests/test_util_file
+/tests/test_set_value
 /tests/*.vg.out
 /tests/*.log
 /tests/*.trs
diff --git a/json_object.c b/json_object.c
index 6eb7ce6..365a76b 100644
--- a/json_object.c
+++ b/json_object.c
@@ -568,6 +568,13 @@ json_bool json_object_get_boolean(const struct json_object *jso)
 	}
 }
 
+int json_object_set_boolean(struct json_object *jso,json_bool new_value){
+	if (!jso || jso->o_type!=json_type_boolean)
+		return 0;
+	jso->o.c_boolean=new_value;
+	return 1;
+}
+
 
 /* json_object_int */
 
@@ -627,6 +634,14 @@ int32_t json_object_get_int(const struct json_object *jso)
   }
 }
 
+int json_object_set_int(struct json_object *jso,int new_value){
+	if (!jso || jso->o_type!=json_type_int)
+		return 0;
+	jso->o.c_int64=new_value;
+	return 1;
+}
+
+
 struct json_object* json_object_new_int64(int64_t i)
 {
 	struct json_object *jso = json_object_new(json_type_int);
@@ -659,6 +674,12 @@ int64_t json_object_get_int64(const struct json_object *jso)
 	}
 }
 
+int json_object_set_int64(struct json_object *jso,int64_t new_value){
+	if (!jso || jso->o_type!=json_type_int)
+		return 0;
+	jso->o.c_int64=new_value;
+	return 1;
+}
 
 /* json_object_double */
 
@@ -720,7 +741,7 @@ int json_object_double_to_json_string(struct json_object* jso,
 				      int flags)
 {
 	return json_object_double_to_json_string_format(jso, pb, level, flags,
-							jso->_userdata);
+							(const char *)jso->_userdata);
 }
 
 struct json_object* json_object_new_double(double d)
@@ -813,6 +834,12 @@ double json_object_get_double(const struct json_object *jso)
   }
 }
 
+int json_object_set_double(struct json_object *jso,double new_value){
+	if (!jso || jso->o_type!=json_type_double)
+		return 0;
+	jso->o.c_double=new_value;
+	return 1;
+}
 
 /* json_object_string */
 
@@ -908,6 +935,27 @@ int json_object_get_string_len(const struct json_object *jso)
 	}
 }
 
+int json_object_set_string(json_object* jso, const char* s) {
+	return json_object_set_string_len(jso, s, (int)(strlen(s)));
+}
+
+int json_object_set_string_len(json_object* jso, const char* s, int len){
+	if (jso==NULL || jso->o_type!=json_type_string) return 0; 	
+	char *dstbuf; 
+	if (len<LEN_DIRECT_STRING_DATA) {
+		dstbuf=jso->o.c_string.str.data;
+		if (jso->o.c_string.len>=LEN_DIRECT_STRING_DATA) free(jso->o.c_string.str.ptr); 
+	} else {
+		dstbuf=(char *)malloc(len+1);
+		if (dstbuf==NULL) return 0;
+		if (jso->o.c_string.len>=LEN_DIRECT_STRING_DATA) free(jso->o.c_string.str.ptr);
+		jso->o.c_string.str.ptr=dstbuf;
+	}
+	jso->o.c_string.len=len;
+	memcpy(dstbuf, (const void *)s, len);
+	dstbuf[len] = '\0';
+	return 1; 
+}
 
 /* json_object_array */
 
diff --git a/json_object.h b/json_object.h
index b6fd917..f86f678 100644
--- a/json_object.h
+++ b/json_object.h
@@ -620,6 +620,19 @@ extern struct json_object* json_object_new_boolean(json_bool b);
 extern json_bool json_object_get_boolean(const struct json_object *obj);
 
 
+/** Set the json_bool value of a json_object
+ * 
+ * The type of obj is checked to be a json_type_boolean and 0 is returned 
+ * if it is not without any further actions. If type of obj is json_type_boolean
+ * the obect value is chaned to new_value
+ *
+ * @param obj the json_object instance
+ * @param new_value the value to be set
+ * @returns 1 if value is set correctly, 0 otherwise
+ */
+extern int json_object_set_boolean(struct json_object *obj,json_bool new_value);
+
+
 /* int type methods */
 
 /** Create a new empty json_object of type json_type_int
@@ -654,6 +667,19 @@ extern struct json_object* json_object_new_int64(int64_t i);
  */
 extern int32_t json_object_get_int(const struct json_object *obj);
 
+/** Set the int value of a json_object
+ * 
+ * The type of obj is checked to be a json_type_int and 0 is returned 
+ * if it is not without any further actions. If type of obj is json_type_int
+ * the obect value is chaned to new_value
+ *
+ * @param obj the json_object instance
+ * @param new_value the value to be set
+ * @returns 1 if value is set correctly, 0 otherwise
+ */
+extern int json_object_set_int(struct json_object *obj,int new_value);
+
+
 /** Get the int value of a json_object
  *
  * The type is coerced to a int64 if the passed object is not a int64.
@@ -670,6 +696,19 @@ extern int32_t json_object_get_int(const struct json_object *obj);
 extern int64_t json_object_get_int64(const struct json_object *obj);
 
 
+/** Set the int64_t value of a json_object
+ * 
+ * The type of obj is checked to be a json_type_int and 0 is returned 
+ * if it is not without any further actions. If type of obj is json_type_int
+ * the obect value is chaned to new_value
+ *
+ * @param obj the json_object instance
+ * @param new_value the value to be set
+ * @returns 1 if value is set correctly, 0 otherwise
+ */
+extern int json_object_set_int64(struct json_object *obj,int64_t new_value);
+
+
 /* double type methods */
 
 /** Create a new empty json_object of type json_type_double
@@ -760,6 +799,20 @@ extern int json_object_double_to_json_string(struct json_object* jso,
 extern double json_object_get_double(const struct json_object *obj);
 
 
+/** Set the double value of a json_object
+ * 
+ * The type of obj is checked to be a json_type_double and 0 is returned 
+ * if it is not without any further actions. If type of obj is json_type_double
+ * the obect value is chaned to new_value
+ *
+ * @param obj the json_object instance
+ * @param new_value the value to be set
+ * @returns 1 if value is set correctly, 0 otherwise
+ */
+extern int json_object_set_double(struct json_object *obj,double new_value);
+
+
+
 /* string type methods */
 
 /** Create a new empty json_object of type json_type_string
@@ -801,6 +854,26 @@ extern const char* json_object_get_string(struct json_object *obj);
  */
 extern int json_object_get_string_len(const struct json_object *obj);
 
+
+/** Set the string value of a json_object with zero terminated strings
+ * equivalent to json_object_set_string_len (obj, new_value, strlen(new_value))
+ * @returns 1 if value is set correctly, 0 otherwise
+ */
+extern int json_object_set_string(json_object* obj, const char* new_value);
+
+/** Set the string value of a json_object str
+ * 
+ * The type of obj is checked to be a json_type_string and 0 is returned 
+ * if it is not without any further actions. If type of obj is json_type_string
+ * the obect value is chaned to new_value
+ *
+ * @param obj the json_object instance
+ * @param new_value the value to be set; Since string legth is given in len this need not be zero terminated
+ * @param len the length of new_value
+ * @returns 1 if value is set correctly, 0 otherwise
+ */
+extern int json_object_set_string_len(json_object* obj, const char* new_value, int len);
+
 /** Check if two json_object's are equal
  *
  * If the passed objects are equal 1 will be returned.
diff --git a/tests/Makefile.am b/tests/Makefile.am
index d33e22c..f6e4b2d 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -21,6 +21,7 @@ TESTS+= test_charcase.test
 TESTS+= test_printbuf.test
 TESTS+= test_set_serializer.test
 TESTS+= test_compare.test
+TESTS+= test_set_value.test
 
 check_PROGRAMS=
 check_PROGRAMS += $(TESTS:.test=)
diff --git a/tests/test_set_value.c b/tests/test_set_value.c
new file mode 100644
index 0000000..4c0a54a
--- /dev/null
+++ b/tests/test_set_value.c
@@ -0,0 +1,52 @@
+#include <assert.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "json.h"
+
+int main(int argc, char **argv)
+{
+	json_object *tmp=json_object_new_int(123);
+	assert (json_object_get_int(tmp)==123);
+	json_object_set_int(tmp,321);
+	assert (json_object_get_int(tmp)==321); 
+	printf("INT PASSED\n");
+	json_object_set_int64(tmp,(int64_t)321321321);
+	assert (json_object_get_int64(tmp)==321321321); 
+	json_object_put(tmp);
+	printf("INT64 PASSED\n");
+	tmp=json_object_new_boolean(TRUE);
+	assert (json_object_get_boolean(tmp)==TRUE); 
+	json_object_set_boolean(tmp,FALSE);
+	assert (json_object_get_boolean(tmp)==FALSE); 
+	json_object_set_boolean(tmp,TRUE);
+	assert (json_object_get_boolean(tmp)==TRUE); 
+	json_object_put(tmp);
+	printf("BOOL PASSED\n");
+	tmp=json_object_new_double(12.34);
+	assert (json_object_get_double(tmp)==12.34); 
+	json_object_set_double(tmp,34.56);
+	assert (json_object_get_double(tmp)==34.56); 
+	json_object_set_double(tmp,6435.34);
+	assert (json_object_get_double(tmp)==6435.34); 
+	json_object_put(tmp);
+	printf("DOUBLE PASSED\n");
+	#define SHORT "SHORT"
+	#define MID   "A MID STRING"
+	//             12345678901234567890123456789012....
+	#define HUGE  "A string longer than 32 chars as to check non local buf codepath"
+	tmp=json_object_new_string(SHORT);
+	assert (strcmp(json_object_get_string(tmp),SHORT)==0); 
+	json_object_set_string(tmp,MID);
+	assert (strcmp(json_object_get_string(tmp),MID)==0); 
+	json_object_set_string(tmp,HUGE);
+	assert (strcmp(json_object_get_string(tmp),HUGE)==0); 
+	json_object_set_string(tmp,SHORT);
+	assert (strcmp(json_object_get_string(tmp),SHORT)==0); 
+	json_object_put(tmp);
+	printf("STRING PASSED\n");
+	
+	
+	printf("PASSED\n");
+	return 0;
+}
diff --git a/tests/test_set_value.expected b/tests/test_set_value.expected
new file mode 100644
index 0000000..6a900f9
--- /dev/null
+++ b/tests/test_set_value.expected
@@ -0,0 +1,6 @@
+INT PASSED
+INT64 PASSED
+BOOL PASSED
+DOUBLE PASSED
+STRING PASSED
+PASSED
diff --git a/tests/test_set_value.test b/tests/test_set_value.test
new file mode 100755
index 0000000..4e8fdac
--- /dev/null
+++ b/tests/test_set_value.test
@@ -0,0 +1,12 @@
+#!/bin/sh
+
+# Common definitions
+if test -z "$srcdir"; then
+    srcdir="${0%/*}"
+    test "$srcdir" = "$0" && srcdir=.
+    test -z "$srcdir" && srcdir=.
+fi
+. "$srcdir/test-defs.sh"
+
+run_output_test test_set_value
+exit $?