diff --git a/libraries/Crypto/utility/ProgMemUtil.h b/libraries/Crypto/utility/ProgMemUtil.h
index ea56224a..41126793 100644
--- a/libraries/Crypto/utility/ProgMemUtil.h
+++ b/libraries/Crypto/utility/ProgMemUtil.h
@@ -25,6 +25,14 @@
 
 #if defined(__AVR__)
 #include <avr/pgmspace.h>
+#define pgm_read_qword(x)   \
+    (__extension__ ({ \
+        const uint32_t *_temp = (const uint32_t *)(x); \
+        ((uint64_t)pgm_read_dword(_temp)) | \
+        (((uint64_t)pgm_read_dword(_temp + 1)) << 32); \
+    }))
+#elif defined(ESP8266)
+#include <pgmspace.h>
 #define pgm_read_qword(x)   \
     (__extension__ ({ \
         const uint32_t *_temp = (const uint32_t *)(x); \