diff --git a/src/lib.rs b/src/lib.rs
index eaec869..27ac2a2 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1954,6 +1954,24 @@ impl From<u64> for BigDecimal {
     }
 }
 
+impl From<i128> for BigDecimal {
+    fn from(n: i128) -> Self {
+        BigDecimal {
+            int_val: BigInt::from(n),
+            scale: 0,
+        }
+    }
+}
+
+impl From<u128> for BigDecimal {
+    fn from(n: u128) -> Self {
+        BigDecimal {
+            int_val: BigInt::from(n),
+            scale: 0,
+        }
+    }
+}
+
 impl From<(BigInt, i64)> for BigDecimal {
     #[inline]
     fn from((int_val, scale): (BigInt, i64)) -> Self {
@@ -2023,6 +2041,16 @@ impl FromPrimitive for BigDecimal {
         Some(BigDecimal::from(n))
     }
 
+    #[inline]
+    fn from_i128(n: i128) -> Option<Self> {
+        Some(BigDecimal::from(n))
+    }
+
+    #[inline]
+    fn from_u128(n: u128) -> Option<Self> {
+        Some(BigDecimal::from(n))
+    }
+
     #[inline]
     fn from_f32(n: f32) -> Option<Self> {
         BigDecimal::try_from(n).ok()
@@ -3285,4 +3313,14 @@ mod bigdecimal_tests {
     fn test_bad_string_only_decimal_and_exponent() {
         BigDecimal::from_str(".e4").unwrap();
     }
+
+    #[test]
+    fn test_from_i128() {
+       BigDecimal::from_i128(-368934881474191032320).unwrap();
+    }
+
+    #[test]
+    fn test_from_u128() {
+       BigDecimal::from_i128(668934881474191032320).unwrap();
+    }
 }