diff --git a/test/Li.jl b/test/Li.jl
index 2abbac7..d232932 100644
--- a/test/Li.jl
+++ b/test/Li.jl
@@ -95,8 +95,10 @@ end
         @test PolyLog.li(n, BigFloat("1.0") + 0im) == PolyLog.zeta(n, BigFloat)
 
         #ForwardDiff Test
-        @test ForwardDiff.derivative(Base.Fix1(PolyLog.reli,n),float(pi)) == PolyLog.reli(n-1,float(pi))/float(pi)
-        @test ForwardDiff.derivative(Base.Fix1(PolyLog.reli,n),0.0) == 1.0
+        if isdefined(Base,:get_extension)
+            @test ForwardDiff.derivative(Base.Fix1(PolyLog.reli,n),float(pi)) == PolyLog.reli(n-1,float(pi))/float(pi)
+            @test ForwardDiff.derivative(Base.Fix1(PolyLog.reli,n),0.0) == 1.0
+        end
     end
 
     # value close to boundary between series 1 and 2 in arXiv:2010.09860
diff --git a/test/Li1.jl b/test/Li1.jl
index 67c7f1d..7cf3b73 100644
--- a/test/Li1.jl
+++ b/test/Li1.jl
@@ -61,6 +61,8 @@
     @test PolyLog.li1(1.0 + 1e300im) ≈ -690.77552789821371 + 1.5707963267948966im rtol=eps(Float64)
 
     #ForwardDiff Test
-    @test ForwardDiff.derivative(PolyLog.reli1,float(pi)) == 1/(1 - pi)
-    @test ForwardDiff.derivative(PolyLog.reli1,0.0) == 1.0
+    if isdefined(Base,:get_extension)
+        @test ForwardDiff.derivative(PolyLog.reli1,float(pi)) == 1/(1 - pi)
+        @test ForwardDiff.derivative(PolyLog.reli1,0.0) == 1.0
+    end
 end
diff --git a/test/Li2.jl b/test/Li2.jl
index cd0f031..c843e39 100644
--- a/test/Li2.jl
+++ b/test/Li2.jl
@@ -68,6 +68,8 @@
     @test PolyLog.li2(1.0 + 1e300im) ≈ -238585.82620504462 + 1085.06766186232im rtol=eps(Float64)
 
     #ForwardDiff Test
-    @test ForwardDiff.derivative(PolyLog.reli2,float(pi)) == PolyLog.reli1(float(pi))/float(pi)
-    @test ForwardDiff.derivative(PolyLog.reli2,0.0) == 1.0
+    if isdefined(Base,:get_extension)
+        @test ForwardDiff.derivative(PolyLog.reli2,float(pi)) == PolyLog.reli1(float(pi))/float(pi)
+        @test ForwardDiff.derivative(PolyLog.reli2,0.0) == 1.0
+    end
 end
diff --git a/test/Li3.jl b/test/Li3.jl
index f3a1f6e..5a2b65e 100644
--- a/test/Li3.jl
+++ b/test/Li3.jl
@@ -62,6 +62,8 @@
     @test PolyLog.li3(1.0 + 1e300im) ≈ -5.4936606061973454e7 + 374771.031356405im rtol=eps(Float64)
 
     #ForwardDiff Test
-    @test ForwardDiff.derivative(PolyLog.reli3,float(pi)) == PolyLog.reli2(float(pi))/float(pi)
-    @test ForwardDiff.derivative(PolyLog.reli3,0.0) == 1.0
+    if isdefined(Base, :ForwardDiff)
+        @test ForwardDiff.derivative(PolyLog.reli3,float(pi)) == PolyLog.reli2(float(pi))/float(pi)
+        @test ForwardDiff.derivative(PolyLog.reli3,0.0) == 1.0
+    end
 end
diff --git a/test/Li4.jl b/test/Li4.jl
index 8e3cf68..9afe139 100644
--- a/test/Li4.jl
+++ b/test/Li4.jl
@@ -54,6 +54,8 @@
     @test PolyLog.li4(1.0 + 1e300im) ≈ -9.4872648206269765e9 + 8.62951114411071e7im rtol=eps(Float64)
 
     #ForwardDiff Test
-    @test ForwardDiff.derivative(PolyLog.reli4,float(pi)) == PolyLog.reli3(float(pi))/float(pi)
-    @test ForwardDiff.derivative(PolyLog.reli4,0.0) == 1.0
+    if isdefined(Base,:get_extension)
+        @test ForwardDiff.derivative(PolyLog.reli4,float(pi)) == PolyLog.reli3(float(pi))/float(pi)
+        @test ForwardDiff.derivative(PolyLog.reli4,0.0) == 1.0
+    end
 end
diff --git a/test/runtests.jl b/test/runtests.jl
index 52a3bac..0079842 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -1,6 +1,8 @@
 using Test
 import PolyLog
-import ForwardDiff
+if isdefined(Base,:get_extension)
+    import ForwardDiff
+end
 
 include("TestPrecision.jl")
 include("DataReader.jl")