diff --git a/changes/v0.12.1 b/changes/v0.12.1
index 140be3c..60c925b 100644
--- a/changes/v0.12.1
+++ b/changes/v0.12.1
@@ -1,3 +1,4 @@
 - fix midpoint method
 - fix posoverflow being returned instead of invaliddigit for parsing ints
-- change debug implementation of parseinterror
\ No newline at end of file
+- change debug implementation of parseinterror
+- fix num-integer lcm implementation for signed ints
\ No newline at end of file
diff --git a/src/bint/numtraits.rs b/src/bint/numtraits.rs
index c71a8f5..9114711 100644
--- a/src/bint/numtraits.rs
+++ b/src/bint/numtraits.rs
@@ -213,7 +213,7 @@ macro_rules! numtraits {
                 if self.is_zero() || other.is_zero() {
                     Self::ZERO
                 } else {
-                    self.div_floor(&self.gcd(other)) * *other
+                    (self.div_floor(&self.gcd(other)) * *other).abs()
                 }
             }
 
diff --git a/src/int/numtraits.rs b/src/int/numtraits.rs
index 033c165..3c2333a 100644
--- a/src/int/numtraits.rs
+++ b/src/int/numtraits.rs
@@ -511,7 +511,8 @@ macro_rules! tests {
                 #[allow(unused_comparisons)]
                 let cond = a.checked_mul(b).is_none() || (a < 0 && a == <$int>::MIN) || (b < 0 && b == <$int>::MIN); // lcm(a, b) <= a * b
                 cond
-            }
+            },
+            cases: [(ref &(1 as $int), ref &(-1i8 as $int))]
         }
         test_bignum! {
             function: <$int as Integer>::gcd(a: ref &$int, b: ref &$int),