diff --git a/libraries/AP_Filesystem/AP_Filesystem.cpp b/libraries/AP_Filesystem/AP_Filesystem.cpp
index e62ec59208..564696bb97 100644
--- a/libraries/AP_Filesystem/AP_Filesystem.cpp
+++ b/libraries/AP_Filesystem/AP_Filesystem.cpp
@@ -290,6 +290,9 @@ bool AP_Filesystem::fgets(char *buf, uint8_t buflen, int fd)
 // run crc32 over file with given name, returns true if successful
 bool AP_Filesystem::crc32(const char *fname, uint32_t& checksum)
 {
+    // Ensure value is initialized
+    checksum = 0;
+
     // Open file in readonly mode
     int fd = open(fname, O_RDONLY);
     if (fd == -1) {