diff --git a/Project.toml b/Project.toml
index c96c631f..2bf7a784 100644
--- a/Project.toml
+++ b/Project.toml
@@ -4,13 +4,13 @@ authors = ["Mosè Giordano <mose@gnu.org>"]
 version = "2.3.0"
 
 [deps]
-Calculus = "49dc2e85-a5d0-5ad3-a950-438e2897f1b9"
+FiniteDifferences = "26cc04aa-876d-5657-8c51-4c34ba976000"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 RecipesBase = "3cdcf5f2-1ef4-517c-9805-6587b60abb01"
 Requires = "ae029012-a4dd-5104-9daa-d747884805df"
 
 [compat]
-Calculus = "0.4.1, 0.5"
+FiniteDifferences = "0.11.5"
 RecipesBase = "0.6.0, 0.7, 0.8, 1.0"
 Requires = "0.5.0, 1"
 julia = "1"
diff --git a/docs/Project.toml b/docs/Project.toml
index cacec142..40d65ab1 100644
--- a/docs/Project.toml
+++ b/docs/Project.toml
@@ -1,8 +1,8 @@
 [deps]
 AutoGrad = "6710c13c-97f1-543f-91c5-74e8f7d95b35"
-Calculus = "49dc2e85-a5d0-5ad3-a950-438e2897f1b9"
 Cuba = "8a292aeb-7a57-582c-b821-06e4c11590b1"
 Documenter = "e30172f5-a6a5-5a46-863b-614d45cd2de4"
+FiniteDifferences = "26cc04aa-876d-5657-8c51-4c34ba976000"
 QuadGK = "1fd47b50-473d-5c70-9696-f719f8f3bcdc"
 SpecialFunctions = "276daf66-3868-5448-9aa4-cd146d93841b"
 Unitful = "1986cc42-f94f-5a68-af5c-568840ba703d"
diff --git a/src/Measurements.jl b/src/Measurements.jl
index 83e31ea6..f8e6fb24 100644
--- a/src/Measurements.jl
+++ b/src/Measurements.jl
@@ -21,9 +21,6 @@ __precompile__()
 
 module Measurements
 
-# Calculus is used to calculate numerical derivatives in "@uncertain" macro.
-using Calculus
-
 using Requires
 
 # Functions provided by this package and exposed to users
diff --git a/src/math.jl b/src/math.jl
index 47d1b6ff..24720bb3 100644
--- a/src/math.jl
+++ b/src/math.jl
@@ -25,6 +25,9 @@
 #
 ### Code:
 
+# FiniteDifferences is used to calculate numerical derivatives in "@uncertain" macro.
+using FiniteDifferences
+
 export @uncertain
 
 # This function is to be used by methods of mathematical operations to produce a
@@ -147,14 +150,14 @@ according to rules of linear error propagation theory.
 
 Function `f` can accept any number of real arguments.
 """
-macro uncertain(expr::Expr)
+macro uncertain(expr::Expr, p::Int=4)
     f = esc(expr.args[1]) # Function name
     n = length(expr.args) - 1
     if n == 1
         a = esc(expr.args[2]) # Argument, of Measurement type
         return quote
             x = measurement($a)
-            result($f(x.val), Calculus.derivative($f, x.val), x)
+            result($f(x.val), FiniteDifferences.central_fdm($(esc(p)), 1)($f, x.val), x)
         end
     else
         a = expr.args[2:end] # Arguments, as an array of expressions
@@ -163,7 +166,8 @@ macro uncertain(expr::Expr)
         argsval =:([])  # Build up the array of values of arguments
         [push!(argsval.args, :($(args.args[i]).val)) for i=1:n] # Fill the array
         return :( result($f($argsval...),
-                         Calculus.gradient(x -> $f(x...), $argsval),
+                         FiniteDifferences.grad(FiniteDifferences.central_fdm($(esc(p)), 1),
+                                                x -> $f(x...), $argsval)[1],
                          $args) )
     end
 end
diff --git a/test/runtests.jl b/test/runtests.jl
index 7032c4da..0d62254c 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -1,4 +1,4 @@
-using Measurements, SpecialFunctions, QuadGK, Calculus
+using Measurements, SpecialFunctions, QuadGK, FiniteDifferences
 using Test, LinearAlgebra, Statistics, Unitful
 
 import Base: isapprox
@@ -295,7 +295,7 @@ end
         end
     end
     for c in (-1 ± 1, 0 ± 1, 1 ± 1)
-        @test sinc(c) ≈ @uncertain(sinc(c)) rtol = 1e-7
+        @test sinc(c) ≈ @uncertain(sinc(c)) atol = 1e-7
         @test cosc(c) ≈ @uncertain(cosc(c)) rtol = 1e-7
         @test Measurements.value(sinc(c) ^ 2 + cosc(c) ^ 2) == 1
     end
@@ -758,11 +758,11 @@ end
         @uncertain((x -> QuadGK.quadgk(exp, 0.4, x)[1])(x))
 end
 
-@testset "Calculus" begin
+@testset "FiniteDifferences" begin
     for a in (w, x, y)
-        @test Calculus.derivative(exp, a + w) ≈ exp(a + w)
-        @test Calculus.derivative(t -> sin(t * x), a) ≈  x * cos(a * x)
-        @test Calculus.derivative(t -> y * cos(t), a) ≈ -y * sin(a)
+        @test FiniteDifferences.central_fdm(5, 1)(exp, a + w) ≈ exp(a + w)
+        @test FiniteDifferences.central_fdm(5, 1)(t -> sin(t * x), a) ≈  x * cos(a * x)
+        @test FiniteDifferences.central_fdm(5, 1)(t -> y * cos(t), a) ≈ -y * sin(a)
     end
 end