diff --git a/test/runtests.jl b/test/runtests.jl
index ba3b8d1..5570210 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -9,7 +9,7 @@ import AbstractFFTs: Plan, fft, ifft, bfft, fft!, ifft!, bfft!,
                      rfft, irfft, brfft, plan_rfft, plan_irfft, plan_brfft,
                      fftshift, ifftshift, plan_inv
 
-# issue #19892
+# Base Julia issue #19892
 # (test this first to make sure it happens before set_num_threads)
 let a = randn(10^5,1), p1 = plan_rfft(a, flags=FFTW.ESTIMATE)
     FFTW.set_num_threads(2)
@@ -326,7 +326,7 @@ let
     FFTW.flops(plan64)
 end
 
-# issue #9772
+# Base Julia issue #9772
 for x in (randn(10),randn(10,12))
     z = complex(x)
     y = rfft(x)
@@ -352,10 +352,97 @@ for x in (randn(10),randn(10,12))
     #       algorithm steps are included in the CTPlan type
 end
 
-# issue #17896
+# Base Julia issue #17896
 a = rand(5)
 @test  fft(a) ==  fft(view(a,:)) ==  fft(view(a, 1:5)) ==  fft(view(a, [1:5;]))
 @test rfft(a) == rfft(view(a,:)) == rfft(view(a, 1:5)) == rfft(view(a, [1:5;]))
 a16 = convert(Vector{Float16}, a)
 @test  fft(a16) ==  fft(view(a16,:)) ==  fft(view(a16, 1:5)) ==  fft(view(a16, [1:5;]))
 @test rfft(a16) == rfft(view(a16,:)) == rfft(view(a16, 1:5)) == rfft(view(a16, [1:5;]))
+
+# Discrete cosine transform (DCT) tests
+
+if FFTW.fftw_vendor() != :mkl
+    a = rand(8,11) + im*rand(8,11)
+    @test norm(idct(dct(a)) - a) < 1e-8
+
+    X = reshape([1,2,7,2,1,5,9,-1,3,4,6,9],3,4)
+    Y = rand(17,14)
+    Y[3:5,9:12] = X
+    sX = view(Y,3:5,9:12)
+
+    true_Xdct = [  13.856406460551018  -3.863239728836245   2.886751345948129  -0.274551994240164; -2.828427124746190  -2.184015211898548  -4.949747468305834   3.966116180118245; 4.898979485566356  -0.194137576915510  -2.857738033247041   2.731723009609389 ]
+
+    true_Xdct_1 = [    5.773502691896258   4.618802153517007   6.350852961085884  10.969655114602890; -4.242640687119286  -2.121320343559643   4.242640687119286  -3.535533905932738; 1.632993161855452   2.041241452319315   5.715476066494083   0.408248290463863 ]
+
+    true_Xdct_2 = [    8.  -3.854030797826254  -3.0  3.761176226848022;
+        4.0  -2.071929829606556   4.0  -2.388955165168770; 12.  -0.765366864730179   4.0  -1.847759065022573 ]
+
+    Xdct = dct(X)
+    Xdct! = float(X); dct!(Xdct!)
+    Xdct_1 = dct(X,1)
+    Xdct!_1 = float(X); dct!(Xdct!_1,1)
+    Xdct_2 = dct(X,2)
+    Xdct!_2 = float(X); dct!(Xdct!_2,2)
+
+    Xidct = idct(true_Xdct)
+    Xidct! = copy(true_Xdct); idct!(Xidct!)
+    Xidct_1 = idct(true_Xdct_1,1)
+    Xidct!_1 = copy(true_Xdct_1); idct!(Xidct!_1,1)
+    Xidct_2 = idct(true_Xdct_2,2)
+    Xidct!_2 = copy(true_Xdct_2); idct!(Xidct!_2,2)
+
+    pXdct = plan_dct(X)*(X)
+    pXdct! = float(X); plan_dct!(pXdct!)*(pXdct!)
+    pXdct_1 = plan_dct(X,1)*(X)
+    pXdct!_1 = float(X); plan_dct!(pXdct!_1,1)*(pXdct!_1)
+    pXdct_2 = plan_dct(X,2)*(X)
+    pXdct!_2 = float(X); plan_dct!(pXdct!_2,2)*(pXdct!_2)
+
+    pXidct = plan_idct(true_Xdct)*(true_Xdct)
+    pXidct! = copy(true_Xdct); plan_idct!(pXidct!)*(pXidct!)
+    pXidct_1 = plan_idct(true_Xdct_1,1)*(true_Xdct_1)
+    pXidct!_1 = copy(true_Xdct_1); plan_idct!(pXidct!_1,1)*(pXidct!_1)
+    pXidct_2 = plan_idct(true_Xdct_2,2)*(true_Xdct_2)
+    pXidct!_2 = copy(true_Xdct_2); plan_idct!(pXidct!_2,2)*(pXidct!_2)
+
+    sXdct = dct(sX)
+    psXdct = plan_dct(sX)*(sX)
+    sYdct! = copy(Y); sXdct! = view(sYdct!,3:5,9:12); dct!(sXdct!)
+    psYdct! = copy(Y); psXdct! = view(psYdct!,3:5,9:12); plan_dct!(psXdct!)*(psXdct!)
+
+    for i = 1:length(X)
+        @test Xdct[i] ≈ true_Xdct[i]
+        @test Xdct![i] ≈ true_Xdct[i]
+        @test Xdct_1[i] ≈ true_Xdct_1[i]
+        @test Xdct!_1[i] ≈ true_Xdct_1[i]
+        @test Xdct_2[i] ≈ true_Xdct_2[i]
+        @test Xdct!_2[i] ≈ true_Xdct_2[i]
+
+        @test pXdct[i] ≈ true_Xdct[i]
+        @test pXdct![i] ≈ true_Xdct[i]
+        @test pXdct_1[i] ≈ true_Xdct_1[i]
+        @test pXdct!_1[i] ≈ true_Xdct_1[i]
+        @test pXdct_2[i] ≈ true_Xdct_2[i]
+        @test pXdct!_2[i] ≈ true_Xdct_2[i]
+
+        @test Xidct[i] ≈ X[i]
+        @test Xidct![i] ≈ X[i]
+        @test Xidct_1[i] ≈ X[i]
+        @test Xidct!_1[i] ≈ X[i]
+        @test Xidct_2[i] ≈ X[i]
+        @test Xidct!_2[i] ≈ X[i]
+
+        @test pXidct[i] ≈ X[i]
+        @test pXidct![i] ≈ X[i]
+        @test pXidct_1[i] ≈ X[i]
+        @test pXidct!_1[i] ≈ X[i]
+        @test pXidct_2[i] ≈ X[i]
+        @test pXidct!_2[i] ≈ X[i]
+
+        @test sXdct[i] ≈ true_Xdct[i]
+        @test psXdct[i] ≈ true_Xdct[i]
+        @test sXdct![i] ≈ true_Xdct[i]
+        @test psXdct![i] ≈ true_Xdct[i]
+    end
+end # fftw_vendor() != :mkl