diff --git a/src/interface.jl b/src/interface.jl
index c7c19df..e7c95c5 100644
--- a/src/interface.jl
+++ b/src/interface.jl
@@ -190,6 +190,10 @@ function operate end
 #     custom `operate` method.
 operate(::typeof(-), x) = -x
 
+# This is not efficient, as it may make unnecessary intermediate copies,
+# but seems like the best way to write a generic implementation.
+operate(::typeof(abs), x) = abs(copy_if_mutable(x))
+
 function operate(
     op::Union{
         typeof(+),
diff --git a/test/interface.jl b/test/interface.jl
index 8c0fac7..3533263 100644
--- a/test/interface.jl
+++ b/test/interface.jl
@@ -97,7 +97,7 @@ end
 @testset "operate" begin
     @testset "$T" for T in (Int, BigInt, Rational{Int})
         x = T(7)
-        @testset "1-ary $op" for op in [+, *, gcd, lcm, copy]
+        @testset "1-ary $op" for op in [+, *, gcd, lcm, copy, abs]
             a = op(x)
             b = MA.operate(op, x)
             @test a == b