diff --git a/src/utils/poly.rs b/src/utils/poly.rs
index ac2b756..f42f1c5 100644
--- a/src/utils/poly.rs
+++ b/src/utils/poly.rs
@@ -575,9 +575,21 @@ pub fn gcd(a: &Polynomial, b: &Polynomial) -> Polynomial {
     if a.is_zero() {
         return b.clone();
     }
+    if b.is_zero() {
+        return a.clone();
+    }
 
-    let monic_b = b.div(&a).1.monic();
-    return gcd(&monic_b, a);
+    if a.degree() > b.degree() {
+        return gcd(b, a);
+    }
+
+    let (_, remainder) = b.div(a);
+
+    if remainder.is_zero() {
+        return a.clone().monic();
+    }
+
+    gcd(&remainder, a)
 }
 
 pub fn non_monic_gcd(a: &Polynomial, b: &Polynomial) -> Polynomial {
diff --git a/test_json/sandbox.json b/test_json/sandbox.json
index d0a0f3c..836b3c8 100644
--- a/test_json/sandbox.json
+++ b/test_json/sandbox.json
@@ -1,18 +1,18 @@
 {
   "testcases": {
     "sandbox": {
-      "action": "gfpoly_factor_ddf",
+      "action": "gfpoly_factor_edf",
       "arguments": {
         "F": [
-          "tpkgAAAAAAAAAAAAAAAAAA==",
-          "m6MQAAAAAAAAAAAAAAAAAA==",
-          "8roAAAAAAAAAAAAAAAAAAA==",
-          "3dUAAAAAAAAAAAAAAAAAAA==",
+          "mmAAAAAAAAAAAAAAAAAAAA==",
+          "AbAAAAAAAAAAAAAAAAAAAA==",
+          "zgAAAAAAAAAAAAAAAAAAAA==",
           "FwAAAAAAAAAAAAAAAAAAAA==",
-          "/kAAAAAAAAAAAAAAAAAAAA==",
-          "a4AAAAAAAAAAAAAAAAAAAA==",
+          "AAAAAAAAAAAAAAAAAAAAAA==",
+          "wAAAAAAAAAAAAAAAAAAAAA==",
           "gAAAAAAAAAAAAAAAAAAAAA=="
-        ]
+        ],
+        "d": 3
       }
     }
   }