diff --git a/libs/native/jna/src/main/java/org/elasticsearch/nativeaccess/jna/JnaPosixCLibrary.java b/libs/native/jna/src/main/java/org/elasticsearch/nativeaccess/jna/JnaPosixCLibrary.java
index ea5bc4c9e3546..c1148ac96aaa4 100644
--- a/libs/native/jna/src/main/java/org/elasticsearch/nativeaccess/jna/JnaPosixCLibrary.java
+++ b/libs/native/jna/src/main/java/org/elasticsearch/nativeaccess/jna/JnaPosixCLibrary.java
@@ -11,6 +11,7 @@
 import com.sun.jna.Library;
 import com.sun.jna.Memory;
 import com.sun.jna.Native;
+import com.sun.jna.NativeLibrary;
 import com.sun.jna.NativeLong;
 import com.sun.jna.Pointer;
 import com.sun.jna.Structure;
@@ -143,9 +144,17 @@ private interface FXStatFunction extends Library {
         this.functions = Native.load("c", NativeFunctions.class);
         FStat64Function fstat64;
         try {
+            // JNA lazily finds symbols, so even though we try to bind two different functions below, if fstat64
+            // isn't found, we won't know until runtime when calling the function. To force resolution of the
+            // symbol we get a function object directly from the native library. We don't use it, we just want to
+            // see if it will throw UnsatisfiedLinkError
+            NativeLibrary.getInstance("c").getFunction("fstat64");
             fstat64 = Native.load("c", FStat64Function.class);
         } catch (UnsatisfiedLinkError e) {
-            // TODO: explain
+            // fstat has a long history in linux from the 32-bit architecture days. On some modern linux systems,
+            // fstat64 doesn't exist as a symbol in glibc. Instead, the compiler replaces fstat64 calls with
+            // the internal __fxstat method. Here we fall back to __fxstat, and staticall bind the special
+            // "version" argument so that the call site looks the same as that of fstat64
             var fxstat = Native.load("c", FXStatFunction.class);
             int version = System.getProperty("os.arch").equals("aarch64") ? 0 : 1;
             fstat64 = (fd, stat) -> fxstat.__fxstat(version, fd, stat);