diff --git a/src/main/c/jpy_jtype.c b/src/main/c/jpy_jtype.c
index 9484e20b..b7895a7d 100644
--- a/src/main/c/jpy_jtype.c
+++ b/src/main/c/jpy_jtype.c
@@ -401,53 +401,63 @@ int JType_CreateJavaObject_2(JNIEnv* jenv, JPy_JType* type, PyObject* pyArg, jcl
     return 0;
 }
 
+#define JType_CALL_STATIC_OBJECT_METHOD_1_AND_RETURN(TARGET_TYPE, STATIC_METHOD_ID, ARG, JOBJECT_PTR) \
+    Py_BEGIN_ALLOW_THREADS; \
+    *JOBJECT_PTR = (*jenv)->CallStaticObjectMethod(jenv, TARGET_TYPE, STATIC_METHOD_ID, ARG); \
+    Py_END_ALLOW_THREADS; \
+    if (*objectRef == NULL) { \
+        PyErr_NoMemory(); \
+        return -1; \
+    } \
+    JPy_ON_JAVA_EXCEPTION_RETURN(-1); \
+    return 0;
+
 int JType_CreateJavaBooleanObject(JNIEnv* jenv, JPy_JType* type, PyObject* pyArg, jobject* objectRef)
 {
-    jvalue value;
+    jboolean value;
     if (PyBool_Check(pyArg) || JPy_IS_CLONG(pyArg)) {
-        value.z = JPy_AS_JBOOLEAN(pyArg);
+        value = JPy_AS_JBOOLEAN(pyArg);
     } else {
         return JType_PythonToJavaConversionError(type, pyArg);
     }
-    return JType_CreateJavaObject(jenv, type, pyArg, JPy_Boolean_JClass, JPy_Boolean_Init_MID, value, objectRef);
+    JType_CALL_STATIC_OBJECT_METHOD_1_AND_RETURN(JPy_Boolean_JClass, JPy_Boolean_ValueOf_SMID, value, objectRef);
 }
 
 int JType_CreateJavaCharacterObject(JNIEnv* jenv, JPy_JType* type, PyObject* pyArg, jobject* objectRef)
 {
-    jvalue value;
+    jchar value;
     if (JPy_IS_CLONG(pyArg)) {
-        value.c = JPy_AS_JCHAR(pyArg);
+        value = JPy_AS_JCHAR(pyArg);
     } else {
         return JType_PythonToJavaConversionError(type, pyArg);
     }
-    return JType_CreateJavaObject(jenv, type, pyArg, JPy_Character_JClass, JPy_Character_Init_MID, value, objectRef);
+    JType_CALL_STATIC_OBJECT_METHOD_1_AND_RETURN(JPy_Character_JClass, JPy_Character_ValueOf_SMID, value, objectRef);
 }
 
 int JType_CreateJavaByteObject(JNIEnv* jenv, JPy_JType* type, PyObject* pyArg, jobject* objectRef)
 {
-    jvalue value;
+    jbyte value;
     if (JPy_IS_CLONG(pyArg)) {
-        value.b = JPy_AS_JBYTE(pyArg);
+        value = JPy_AS_JBYTE(pyArg);
     } else {
         return JType_PythonToJavaConversionError(type, pyArg);
     }
-    return JType_CreateJavaObject(jenv, type, pyArg, JPy_Byte_JClass, JPy_Byte_Init_MID, value, objectRef);
+    JType_CALL_STATIC_OBJECT_METHOD_1_AND_RETURN(JPy_Byte_JClass, JPy_Byte_ValueOf_SMID, value, objectRef);
 }
 
 int JType_CreateJavaShortObject(JNIEnv* jenv, JPy_JType* type, PyObject* pyArg, jobject* objectRef)
 {
-    jvalue value;
+    jshort value;
     if (JPy_IS_CLONG(pyArg)) {
-        value.s = JPy_AS_JSHORT(pyArg);
+        value = JPy_AS_JSHORT(pyArg);
     } else {
         return JType_PythonToJavaConversionError(type, pyArg);
     }
-    return JType_CreateJavaObject(jenv, type, pyArg, JPy_Short_JClass, JPy_Short_Init_MID, value, objectRef);
+    JType_CALL_STATIC_OBJECT_METHOD_1_AND_RETURN(JPy_Short_JClass, JPy_Short_ValueOf_SMID, value, objectRef);
 }
 
 int JType_CreateJavaNumberFromPythonInt(JNIEnv* jenv, JPy_JType* type, PyObject* pyArg, jobject* objectRef)
 {
-    jvalue value;
     signed char b;
     short s;
     long i;
@@ -458,69 +468,63 @@ int JType_CreateJavaNumberFromPythonInt(JNIEnv* jenv, JPy_JType* type, PyObject*
     b = (signed char) j;
 
     if (i != j) {
-        value.j = j;
-        return JType_CreateJavaObject(jenv, type, pyArg, JPy_Long_JClass, JPy_Long_Init_MID, value, objectRef);
+        JType_CALL_STATIC_OBJECT_METHOD_1_AND_RETURN(JPy_Long_JClass, JPy_Long_ValueOf_SMID, j, objectRef);
     }
     if (s != i) {
-        value.i = i;
-        return JType_CreateJavaObject(jenv, type, pyArg, JPy_Integer_JClass, JPy_Integer_Init_MID, value,
-                                     objectRef);
+        JType_CALL_STATIC_OBJECT_METHOD_1_AND_RETURN(JPy_Integer_JClass, JPy_Integer_ValueOf_SMID, i, objectRef);
     }
     if (b != s) {
-        value.s = s;
-        return JType_CreateJavaObject(jenv, type, pyArg, JPy_Short_JClass, JPy_Short_Init_MID, value,
-                                      objectRef);
+        JType_CALL_STATIC_OBJECT_METHOD_1_AND_RETURN(JPy_Short_JClass, JPy_Short_ValueOf_SMID, s, objectRef);
     }
-    value.b = b;
-    return JType_CreateJavaObject(jenv, type, pyArg, JPy_Byte_JClass, JPy_Byte_Init_MID, value, objectRef);
+    JType_CALL_STATIC_OBJECT_METHOD_1_AND_RETURN(JPy_Byte_JClass, JPy_Byte_ValueOf_SMID, b, objectRef);
 }
 
 int JType_CreateJavaIntegerObject(JNIEnv* jenv, JPy_JType* type, PyObject* pyArg, jobject* objectRef)
 {
-    jvalue value;
+    jint value;
     if (JPy_IS_CLONG(pyArg)) {
-        value.i = JPy_AS_JINT(pyArg);
+        value = JPy_AS_JINT(pyArg);
     } else {
         return JType_PythonToJavaConversionError(type, pyArg);
     }
-    return JType_CreateJavaObject(jenv, type, pyArg, JPy_Integer_JClass, JPy_Integer_Init_MID, value, objectRef);
+    JType_CALL_STATIC_OBJECT_METHOD_1_AND_RETURN(JPy_Integer_JClass, JPy_Integer_ValueOf_SMID, value, objectRef);
 }
 
 int JType_CreateJavaLongObject(JNIEnv* jenv, JPy_JType* type, PyObject* pyArg, jobject* objectRef)
 {
-    jvalue value;
+    jlong value;
     if (JPy_IS_CLONG(pyArg)) {
-        value.j = JPy_AS_JLONG(pyArg);
+        value = JPy_AS_JLONG(pyArg);
     } else {
         return JType_PythonToJavaConversionError(type, pyArg);
     }
-    return JType_CreateJavaObject(jenv, type, pyArg, JPy_Long_JClass, JPy_Long_Init_MID, value, objectRef);
+    JType_CALL_STATIC_OBJECT_METHOD_1_AND_RETURN(JPy_Long_JClass, JPy_Long_ValueOf_SMID, value, objectRef);
 }
 
 int JType_CreateJavaFloatObject(JNIEnv* jenv, JPy_JType* type, PyObject* pyArg, jobject* objectRef)
 {
-    jvalue value;
+    jfloat value;
     if (JPy_IS_CLONG(pyArg)) {
-        value.f = (jfloat) JPy_AS_JLONG(pyArg);
+        value = (jfloat) JPy_AS_JLONG(pyArg);
     } else if (PyFloat_Check(pyArg)) {
-        value.f = JPy_AS_JFLOAT(pyArg);
+        value = JPy_AS_JFLOAT(pyArg);
     } else {
         return JType_PythonToJavaConversionError(type, pyArg);
     }
-    return JType_CreateJavaObject(jenv, type, pyArg, JPy_Float_JClass, JPy_Float_Init_MID, value, objectRef);
+    JType_CALL_STATIC_OBJECT_METHOD_1_AND_RETURN(JPy_Float_JClass, JPy_Float_ValueOf_SMID, value, objectRef);
 }
 
 int JType_CreateJavaDoubleObject(JNIEnv* jenv, JPy_JType* type, PyObject* pyArg, jobject* objectRef)
 {
-    jvalue value;
+    jdouble value;
     if (JPy_IS_CLONG(pyArg)) {
-        value.d = (jdouble) JPy_AS_JLONG(pyArg);
+        value = (jdouble) JPy_AS_JLONG(pyArg);
     } else if (PyFloat_Check(pyArg)) {
-        value.d = JPy_AS_JDOUBLE(pyArg);
+        value = JPy_AS_JDOUBLE(pyArg);
     } else {
         return JType_PythonToJavaConversionError(type, pyArg);
     }
-    return JType_CreateJavaObject(jenv, type, pyArg, JPy_Double_JClass, JPy_Double_Init_MID, value, objectRef);
+    JType_CALL_STATIC_OBJECT_METHOD_1_AND_RETURN(JPy_Double_JClass, JPy_Double_ValueOf_SMID, value, objectRef);
 }
 
 int JType_CreateJavaPyObject(JNIEnv* jenv, JPy_JType* type, PyObject* pyArg, jobject* objectRef)
diff --git a/src/main/c/jpy_module.c b/src/main/c/jpy_module.c
index e41df14e..e8716fca 100644
--- a/src/main/c/jpy_module.c
+++ b/src/main/c/jpy_module.c
@@ -193,30 +193,30 @@ jclass JPy_StopIteration_JClass = NULL;
 
 // java.lang.Boolean
 jclass JPy_Boolean_JClass = NULL;
-jmethodID JPy_Boolean_Init_MID = NULL;
+jmethodID JPy_Boolean_ValueOf_SMID = NULL;
 jmethodID JPy_Boolean_BooleanValue_MID = NULL;
 
 jclass JPy_Character_JClass = NULL;
-jmethodID JPy_Character_Init_MID;
+jmethodID JPy_Character_ValueOf_SMID;
 jmethodID JPy_Character_CharValue_MID = NULL;
 
 jclass JPy_Byte_JClass = NULL;
-jmethodID JPy_Byte_Init_MID = NULL;
+jmethodID JPy_Byte_ValueOf_SMID = NULL;
 
 jclass JPy_Short_JClass = NULL;
-jmethodID JPy_Short_Init_MID = NULL;
+jmethodID JPy_Short_ValueOf_SMID = NULL;
 
 jclass JPy_Integer_JClass = NULL;
-jmethodID JPy_Integer_Init_MID = NULL;
+jmethodID JPy_Integer_ValueOf_SMID = NULL;
 
 jclass JPy_Long_JClass = NULL;
-jmethodID JPy_Long_Init_MID = NULL;
+jmethodID JPy_Long_ValueOf_SMID = NULL;
 
 jclass JPy_Float_JClass = NULL;
-jmethodID JPy_Float_Init_MID = NULL;
+jmethodID JPy_Float_ValueOf_SMID = NULL;
 
 jclass JPy_Double_JClass = NULL;
-jmethodID JPy_Double_Init_MID = NULL;
+jmethodID JPy_Double_ValueOf_SMID = NULL;
 
 // java.lang.Number
 jclass JPy_Number_JClass = NULL;
@@ -890,32 +890,32 @@ int JPy_InitGlobalVars(JNIEnv* jenv)
     DEFINE_CLASS(JPy_UnsupportedOperationException_JClass, "java/lang/UnsupportedOperationException");
 
     DEFINE_CLASS(JPy_Boolean_JClass, "java/lang/Boolean");
-    DEFINE_METHOD(JPy_Boolean_Init_MID, JPy_Boolean_JClass, "<init>", "(Z)V");
+    DEFINE_STATIC_METHOD(JPy_Boolean_ValueOf_SMID, JPy_Boolean_JClass, "valueOf", "(Z)Ljava/lang/Boolean;");
     DEFINE_METHOD(JPy_Boolean_BooleanValue_MID, JPy_Boolean_JClass, "booleanValue", "()Z");
 
     DEFINE_CLASS(JPy_Character_JClass, "java/lang/Character");
-    DEFINE_METHOD(JPy_Character_Init_MID, JPy_Character_JClass, "<init>", "(C)V");
+    DEFINE_STATIC_METHOD(JPy_Character_ValueOf_SMID, JPy_Character_JClass, "valueOf", "(C)Ljava/lang/Character;");
     DEFINE_METHOD(JPy_Character_CharValue_MID, JPy_Character_JClass, "charValue", "()C");
 
     DEFINE_CLASS(JPy_Number_JClass, "java/lang/Number");
 
     DEFINE_CLASS(JPy_Byte_JClass, "java/lang/Byte");
-    DEFINE_METHOD(JPy_Byte_Init_MID, JPy_Byte_JClass, "<init>", "(B)V");
+    DEFINE_STATIC_METHOD(JPy_Byte_ValueOf_SMID, JPy_Byte_JClass, "valueOf", "(B)Ljava/lang/Byte;");
 
     DEFINE_CLASS(JPy_Short_JClass, "java/lang/Short");
-    DEFINE_METHOD(JPy_Short_Init_MID, JPy_Short_JClass, "<init>", "(S)V");
+    DEFINE_STATIC_METHOD(JPy_Short_ValueOf_SMID, JPy_Short_JClass, "valueOf", "(S)Ljava/lang/Short;");
 
     DEFINE_CLASS(JPy_Integer_JClass, "java/lang/Integer");
-    DEFINE_METHOD(JPy_Integer_Init_MID, JPy_Integer_JClass, "<init>", "(I)V");
+    DEFINE_STATIC_METHOD(JPy_Integer_ValueOf_SMID, JPy_Integer_JClass, "valueOf", "(I)Ljava/lang/Integer;");
 
     DEFINE_CLASS(JPy_Long_JClass, "java/lang/Long");
-    DEFINE_METHOD(JPy_Long_Init_MID, JPy_Long_JClass, "<init>", "(J)V");
+    DEFINE_STATIC_METHOD(JPy_Long_ValueOf_SMID, JPy_Long_JClass, "valueOf", "(J)Ljava/lang/Long;");
 
     DEFINE_CLASS(JPy_Float_JClass, "java/lang/Float");
-    DEFINE_METHOD(JPy_Float_Init_MID, JPy_Float_JClass, "<init>", "(F)V");
+    DEFINE_STATIC_METHOD(JPy_Float_ValueOf_SMID, JPy_Float_JClass, "valueOf", "(F)Ljava/lang/Float;");
 
     DEFINE_CLASS(JPy_Double_JClass, "java/lang/Double");
-    DEFINE_METHOD(JPy_Double_Init_MID, JPy_Double_JClass, "<init>", "(D)V");
+    DEFINE_STATIC_METHOD(JPy_Double_ValueOf_SMID, JPy_Double_JClass, "valueOf", "(D)Ljava/lang/Double;");
 
     DEFINE_CLASS(JPy_Number_JClass, "java/lang/Number");
     DEFINE_METHOD(JPy_Number_IntValue_MID, JPy_Number_JClass, "intValue", "()I");
@@ -1036,16 +1036,16 @@ void JPy_ClearGlobalVars(JNIEnv* jenv)
     JPy_Field_GetName_MID = NULL;
     JPy_Field_GetModifiers_MID = NULL;
     JPy_Field_GetType_MID = NULL;
-    JPy_Boolean_Init_MID = NULL;
+    JPy_Boolean_ValueOf_SMID = NULL;
     JPy_Boolean_BooleanValue_MID = NULL;
-    JPy_Character_Init_MID = NULL;
+    JPy_Character_ValueOf_SMID = NULL;
     JPy_Character_CharValue_MID = NULL;
-    JPy_Byte_Init_MID = NULL;
-    JPy_Short_Init_MID = NULL;
-    JPy_Integer_Init_MID = NULL;
-    JPy_Long_Init_MID = NULL;
-    JPy_Float_Init_MID = NULL;
-    JPy_Double_Init_MID = NULL;
+    JPy_Byte_ValueOf_SMID = NULL;
+    JPy_Short_ValueOf_SMID = NULL;
+    JPy_Integer_ValueOf_SMID = NULL;
+    JPy_Long_ValueOf_SMID = NULL;
+    JPy_Float_ValueOf_SMID = NULL;
+    JPy_Double_ValueOf_SMID = NULL;
     JPy_Number_IntValue_MID = NULL;
     JPy_Number_LongValue_MID = NULL;
     JPy_Number_DoubleValue_MID = NULL;
diff --git a/src/main/c/jpy_module.h b/src/main/c/jpy_module.h
index 3e260d1f..36b48f31 100644
--- a/src/main/c/jpy_module.h
+++ b/src/main/c/jpy_module.h
@@ -215,32 +215,32 @@ extern jclass JPy_KeyError_JClass;
 extern jclass JPy_StopIteration_JClass;
 
 extern jclass JPy_Boolean_JClass;
-extern jmethodID JPy_Boolean_Init_MID;
+extern jmethodID JPy_Boolean_ValueOf_SMID;
 extern jmethodID JPy_Boolean_BooleanValue_MID;
 
 extern jclass JPy_Character_JClass;
-extern jmethodID JPy_Character_Init_MID;
+extern jmethodID JPy_Character_ValueOf_SMID;
 extern jmethodID JPy_Character_CharValue_MID;
 
 extern jclass JPy_Number_JClass;
 
 extern jclass JPy_Byte_JClass;
-extern jmethodID JPy_Byte_Init_MID;
+extern jmethodID JPy_Byte_ValueOf_SMID;
 
 extern jclass JPy_Short_JClass;
-extern jmethodID JPy_Short_Init_MID;
+extern jmethodID JPy_Short_ValueOf_SMID;
 
 extern jclass JPy_Integer_JClass;
-extern jmethodID JPy_Integer_Init_MID;
+extern jmethodID JPy_Integer_ValueOf_SMID;
 
 extern jclass JPy_Long_JClass;
-extern jmethodID JPy_Long_Init_MID;
+extern jmethodID JPy_Long_ValueOf_SMID;
 
 extern jclass JPy_Float_JClass;
-extern jmethodID JPy_Float_Init_MID;
+extern jmethodID JPy_Float_ValueOf_SMID;
 
 extern jclass JPy_Double_JClass;
-extern jmethodID JPy_Double_Init_MID;
+extern jmethodID JPy_Double_ValueOf_SMID;
 
 extern jclass JPy_Number_JClass;
 extern jmethodID JPy_Number_IntValue_MID;