Two libraries collide. Ambiguous functions/variables?

I get several errors once I try to include these two libraries:

error: expected unqualified-id before '{' token #define DEBUG_PRINTLN(...) {}

#include <DHT.h>
#include <DGS.h>

void setup() {
}

void loop() {
}

Apparently DEBUG_PRINTLN is causing the problems, because it is defined as a private function in DGS.h and as a constant (#define) in DHT.h.

Including DGS.h before DHT.h does not throw errors. But is this a safe workaround or might I run into errors later? How can I deal with that, without modifying the libraries?

DGS.h:

/*
  DGS_25SEP17.h - Library for reading KWJ Engineering with SPEC Sensors on Digital SDK with firmware date 25SEP17.
  Created by David E. Peaslee, Mar 29, 2018.
*/

#ifndef _DGS_h
#define _DGS_h

#if defined(ARDUINO) && ARDUINO >= 100
#include "Arduino.h"
#elif defined(SPARK)
//#include "application.h"
#else
#include "WProgram.h"
#endif

#include "Stream.h"

class DGS
{
  private:
    Stream *_mySerial;
    long dataArray[11]; //Multipurpose array
    //void unlock(void);
    void DEBUG_PRINTLN(long x);
    void DEBUG_PRINTLN(float x);
    void DEBUG_PRINTLN(String x);
    void DEBUG_PRINT(long x);
    void DEBUG_PRINT(float x);
    void DEBUG_PRINT(String x);

  public:
    DGS(Stream &mySerial); //Class that represents DULP with Stream as class for Serial
    DGS(Stream *mySerial); //Class that represents DULP with Stream as class for Serial

    bool DEBUG;

    int setToff(float offset);  //Sets a temperature offset
    int setBC(String BC);  //Initializes DGS with all information from barcode, only way to set Span
    String getFW(void); //Returns the Firmware Date

    int getLMP(void); //Loads LMP[3] with register values from LMP91000
    int LMP[3];  //LMP Registers, needs to be loaded with getLMP
    int setLMP(int R1, int R2, int R3); //Sets new LMP registers and reintializes LMP

    int zero(void); //Zeros to current reading, Zero only in a clean air environment
    int setXSpan(float); //ReCalibrates device, only should be used after zero, and using a calibrated gas

    int getData(char c); //Gets the data and loads into variables
    long getConc(char x = 'p');  //Reads concentration from current data array 'p' ppb or 'c' counts
    long getTemp(char t = 'C');  //Reads temperature from current data array 'C' for Celsius or 'F' for Fahrenheit
    long getRh(char r = 'r'); //Reads Rh from current data array 'r' for Rh and 'c' for counts

    void getEEPROM(void); //Loads variables into EEPROM E[5] and e[14] arrays, outputs EEPROM if DEBUG is true
    String eepromStr[5]; //Stores the character based EEPROM data
    long eepromInt[13];  //Stores the integer based EEPROM data
    float Sensitivity_Code;  //Stores the sensitivity coefficient in nA/PPM
};

#endif

DHT.h:

/* DHT library

MIT license
written by Adafruit Industries
*/
#ifndef DHT_H
#define DHT_H

#if ARDUINO >= 100
 #include "Arduino.h"
#else
 #include "WProgram.h"
#endif


// Uncomment to enable printing out nice debug messages.
//#define DHT_DEBUG

// Define where debug output will be printed.
#define DEBUG_PRINTER Serial

// Setup debug printing macros.
#ifdef DHT_DEBUG
  #define DEBUG_PRINT(...) { DEBUG_PRINTER.print(__VA_ARGS__); }
  #define DEBUG_PRINTLN(...) { DEBUG_PRINTER.println(__VA_ARGS__); }
#else
  #define DEBUG_PRINT(...) {}
  #define DEBUG_PRINTLN(...) {}
#endif

// Define types of sensors.
#define DHT11 11
#define DHT12 12
#define DHT22 22
#define DHT21 21
#define AM2301 21


class DHT {
  public:
   DHT(uint8_t pin, uint8_t type, uint8_t count=6);
   void begin(uint8_t usec=55);
   float readTemperature(bool S=false, bool force=false);
   float convertCtoF(float);
   float convertFtoC(float);
   float computeHeatIndex(bool isFahrenheit=true);
   float computeHeatIndex(float temperature, float percentHumidity, bool isFahrenheit=true);
   float readHumidity(bool force=false);
   bool read(bool force=false);

 private:
  uint8_t data[5];
  uint8_t _pin, _type;
  #ifdef __AVR
    // Use direct GPIO access on an 8-bit AVR so keep track of the port and bitmask
    // for the digital pin connected to the DHT.  Other platforms will use digitalRead.
    uint8_t _bit, _port;
  #endif
  uint32_t _lastreadtime, _maxcycles;
  bool _lastresult;
  uint8_t pullTime; // Time (in usec) to pull up data line before reading

  uint32_t expectPulse(bool level);

};

class InterruptLock {
  public:
   InterruptLock() {
#if !defined(ARDUINO_ARCH_NRF52)  
    noInterrupts();
#endif
   }
   ~InterruptLock() {
#if !defined(ARDUINO_ARCH_NRF52)  
    interrupts();
#endif
   }
};

#endif