diff --git a/contrib/51d/trie/51Degrees.c b/contrib/51d/trie/51Degrees.c
new file mode 100644
index 0000000..7453061
--- /dev/null
+++ b/contrib/51d/trie/51Degrees.c
@@ -0,0 +1,89 @@
+/* *********************************************************************
+ * This Source Code Form is copyright of 51Degrees Mobile Experts Limited.
+ * Copyright 2019 51Degrees Mobile Experts Limited, 5 Charlotte Close,
+ * Caversham, Reading, Berkshire, United Kingdom RG4 7BY
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0.
+ *
+ * If a copy of the MPL was not distributed with this file, You can obtain
+ * one at http://mozilla.org/MPL/2.0/.
+ *
+ * This Source Code Form is "Incompatible With Secondary Licenses", as
+ * defined by the Mozilla Public License, v. 2.0.
+ * *********************************************************************/
+
+/* *********************************************************************
+ * Dummy library for HAProxy. This does not function, and is designed
+ * solely for HAProxy testing purposes.
+ * *********************************************************************/
+#include "51Degrees.h"
+#include <stdlib.h>
+
+int fiftyoneDegreesGetDeviceOffset(
+	fiftyoneDegreesDataSet *dataSet,
+	const char *userAgent) {
+    return 0;
+}
+
+const char** fiftyoneDegreesGetRequiredPropertiesNames(
+	fiftyoneDegreesDataSet *dataSet) {
+    return NULL;
+}
+
+int fiftyoneDegreesGetRequiredPropertiesCount(
+	fiftyoneDegreesDataSet *dataSet) {
+    return 0;
+}
+
+int fiftyoneDegreesGetValueFromOffsets(
+	fiftyoneDegreesDataSet *dataSet,
+	fiftyoneDegreesDeviceOffsets* deviceOffsets,
+	int requiredPropertyIndex,
+	char* values,
+	int size) {
+    return 0;
+}
+
+static fiftyoneDegreesDeviceOffset dummyOffset = { 0, 0, "dummy-user-agent" };
+
+static fiftyoneDegreesDeviceOffsets dummyOffsets = { 1, &dummyOffset, NULL };
+
+fiftyoneDegreesDeviceOffsets* fiftyoneDegreesCreateDeviceOffsets(
+	fiftyoneDegreesDataSet *dataSet) {
+    return &dummyOffsets;
+}
+
+void fiftyoneDegreesFreeDeviceOffsets(
+	fiftyoneDegreesDeviceOffsets* offsets) {
+    return;
+}
+
+int fiftyoneDegreesGetHttpHeaderCount(
+	fiftyoneDegreesDataSet *dataSet) {
+    return 0;
+}
+
+int fiftyoneDegreesGetHttpHeaderNameOffset(
+	fiftyoneDegreesDataSet *dataSet,
+	int httpHeaderIndex) {
+    return 0;
+}
+
+const char* fiftyoneDegreesGetHttpHeaderNamePointer(
+	fiftyoneDegreesDataSet *dataSet,
+	int httpHeaderIndex) {
+    return "dummy-header-name";
+}
+
+fiftyoneDegreesDataSetInitStatus fiftyoneDegreesInitWithPropertyArray(
+	const char* fileName,
+	fiftyoneDegreesDataSet *dataSet,
+	const char** properties,
+	int propertyCount) {
+    return DATA_SET_INIT_STATUS_SUCCESS;
+}
+
+void fiftyoneDegreesDataSetFree(fiftyoneDegreesDataSet *dataSet) {
+    return;
+}
\ No newline at end of file
diff --git a/contrib/51d/trie/51Degrees.h b/contrib/51d/trie/51Degrees.h
new file mode 100644
index 0000000..a5f0868
--- /dev/null
+++ b/contrib/51d/trie/51Degrees.h
@@ -0,0 +1,108 @@
+/* *********************************************************************
+ * This Source Code Form is copyright of 51Degrees Mobile Experts Limited.
+ * Copyright 2019 51Degrees Mobile Experts Limited, 5 Charlotte Close,
+ * Caversham, Reading, Berkshire, United Kingdom RG4 7BY
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0.
+ *
+ * If a copy of the MPL was not distributed with this file, You can obtain
+ * one at http://mozilla.org/MPL/2.0/.
+ *
+ * This Source Code Form is "Incompatible With Secondary Licenses", as
+ * defined by the Mozilla Public License, v. 2.0.
+ * *********************************************************************/
+
+/* *********************************************************************
+ * Dummy library for HAProxy. This does not function, and is designed
+ * solely for HAProxy testing purposes.
+ * *********************************************************************/
+#ifndef FIFTYONEDEGREES_H_INCLUDED
+#define FIFTYONEDEGREES_H_INCLUDED
+
+#ifndef FIFTYONEDEGREES_H_TRIE_INCLUDED
+#define FIFTYONEDEGREES_H_TRIE_INCLUDED
+#endif
+
+#include <stdint.h>
+
+typedef enum e_fiftyoneDegrees_DataSetInitStatus {
+	DATA_SET_INIT_STATUS_SUCCESS,
+	DATA_SET_INIT_STATUS_INSUFFICIENT_MEMORY,
+	DATA_SET_INIT_STATUS_CORRUPT_DATA,
+	DATA_SET_INIT_STATUS_INCORRECT_VERSION,
+	DATA_SET_INIT_STATUS_FILE_NOT_FOUND,
+	DATA_SET_INIT_STATUS_NOT_SET,
+	DATA_SET_INIT_STATUS_POINTER_OUT_OF_BOUNDS,
+	DATA_SET_INIT_STATUS_NULL_POINTER
+} fiftyoneDegreesDataSetInitStatus;
+
+typedef struct fiftyoneDegrees_integers_t {
+	int32_t *firstElement;
+	unsigned int count;
+	int freeMemory;
+} fiftyoneDegreesIntegers;
+
+typedef struct fiftyoneDegrees_dataset_t {
+    fiftyoneDegreesIntegers uniqueHttpHeaders;
+} fiftyoneDegreesDataSet;
+
+typedef struct fiftyoneDegrees_active_dataset_t {
+
+} fiftyoneDegreesActiveDataSet;
+
+typedef struct fiftyoneDegrees_device_offset_t {
+    int httpHeaderOffset;
+    int deviceOffset;
+    char *userAgent;
+} fiftyoneDegreesDeviceOffset;
+
+typedef struct fiftyoneDegrees_device_offsets_t {
+    int size;
+	fiftyoneDegreesDeviceOffset *firstOffset;
+	fiftyoneDegreesActiveDataSet *active;
+} fiftyoneDegreesDeviceOffsets;
+
+int fiftyoneDegreesGetDeviceOffset(
+	fiftyoneDegreesDataSet *dataSet,
+	const char *userAgent);
+
+const char** fiftyoneDegreesGetRequiredPropertiesNames(
+	fiftyoneDegreesDataSet *dataSet);
+
+int fiftyoneDegreesGetRequiredPropertiesCount(
+	fiftyoneDegreesDataSet *dataSet);
+
+int fiftyoneDegreesGetValueFromOffsets(
+	fiftyoneDegreesDataSet *dataSet,
+	fiftyoneDegreesDeviceOffsets* deviceOffsets,
+	int requiredPropertyIndex,
+	char* values,
+	int size);
+
+fiftyoneDegreesDeviceOffsets* fiftyoneDegreesCreateDeviceOffsets(
+	fiftyoneDegreesDataSet *dataSet);
+
+void fiftyoneDegreesFreeDeviceOffsets(
+	fiftyoneDegreesDeviceOffsets* offsets);
+
+int fiftyoneDegreesGetHttpHeaderCount(
+	fiftyoneDegreesDataSet *dataSet);
+
+int fiftyoneDegreesGetHttpHeaderNameOffset(
+	fiftyoneDegreesDataSet *dataSet,
+	int httpHeaderIndex);
+
+const char* fiftyoneDegreesGetHttpHeaderNamePointer(
+	fiftyoneDegreesDataSet *dataSet,
+	int httpHeaderIndex);
+
+fiftyoneDegreesDataSetInitStatus fiftyoneDegreesInitWithPropertyArray(
+	const char* fileName,
+	fiftyoneDegreesDataSet *dataSet,
+	const char** properties,
+	int propertyCount);
+
+void fiftyoneDegreesDataSetFree(fiftyoneDegreesDataSet *dataSet);
+
+#endif
\ No newline at end of file