diff --git a/src/t/Makefile.am b/src/t/Makefile.am
index e6d91686..11755436 100644
--- a/src/t/Makefile.am
+++ b/src/t/Makefile.am
@@ -20,7 +20,7 @@ test_math_SOURCES = test-common.cpp \
     math/array2d.cpp math/array3d.cpp math/arraynd.cpp math/box.cpp \
     math/cmplx.cpp math/half.cpp math/interp.cpp math/matrix.cpp \
     math/quat.cpp math/rand.cpp math/real.cpp math/rotation.cpp \
-    math/trig.cpp math/vector.cpp
+    math/trig.cpp math/vector.cpp math/simplex_interpolator.cpp
 test_math_CPPFLAGS = $(AM_CPPFLAGS) -I$(top_srcdir)/tools/lolunit
 test_math_DEPENDENCIES = @LOL_DEPS@
 
diff --git a/src/t/math/simplex_interpolator.cpp b/src/t/math/simplex_interpolator.cpp
index aba46ff4..35737ae8 100644
--- a/src/t/math/simplex_interpolator.cpp
+++ b/src/t/math/simplex_interpolator.cpp
@@ -61,6 +61,12 @@ lolunit_declare_fixture(SimplexInterpolatorTest)
 
     void TearDown() {}
 
+    lolunit_declare_test(CompoundVariable)
+    {
+        test_interpolator<2, real> b({{ real(0) }});
+        test_interpolator<2, vec2> c({{ vec2(0) }});
+    }
+
     lolunit_declare_test(CoordinateMatrixTest)
     {
         test_interpolator<2> s2({{1.f}});