diff --git a/src/stdlib/SDL_crc16.c b/src/stdlib/SDL_crc16.c
index db011ba10..0008b2e3e 100644
--- a/src/stdlib/SDL_crc16.c
+++ b/src/stdlib/SDL_crc16.c
@@ -25,6 +25,9 @@
 
 /* Public domain CRC implementation adapted from:
    http://home.thep.lu.se/~bjorn/crc/crc32_simple.c
+
+   This algorithm is compatible with the 16-bit CRC described here:
+   https://www.lammertbies.nl/comm/info/crc-calculation
 */
 /* NOTE: DO NOT CHANGE THIS ALGORITHM
    There is code that relies on this in the joystick code
diff --git a/src/stdlib/SDL_crc32.c b/src/stdlib/SDL_crc32.c
index 505689661..cd7229c96 100644
--- a/src/stdlib/SDL_crc32.c
+++ b/src/stdlib/SDL_crc32.c
@@ -25,6 +25,9 @@
 
 /* Public domain CRC implementation adapted from:
    http://home.thep.lu.se/~bjorn/crc/crc32_simple.c
+
+   This algorithm is compatible with the 32-bit CRC described here:
+   https://www.lammertbies.nl/comm/info/crc-calculation
 */
 /* NOTE: DO NOT CHANGE THIS ALGORITHM
    There is code that relies on this in the joystick code