cmake: Build tests with the static library.

Signed-off-by: Andreas Schneider <asn@cryptomilk.org>
diff --git a/DefineOptions.cmake b/DefineOptions.cmake
index d34d2a3..7564a22 100644
--- a/DefineOptions.cmake
+++ b/DefineOptions.cmake
@@ -1,3 +1,7 @@
 option(WITH_STATIC_LIB "Build with a static library" OFF)
 option(WITH_CMOCKERY_SUPPORT "Install a cmockery header" OFF)
 option(UNIT_TESTING "Build with unit testing" OFF)
+
+if (UNIT_TESTING)
+    set(WITH_STATIC_LIB ON)
+endif()
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 1be4867..e10985b 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -19,14 +19,14 @@
     test_setup_fail)
 
 foreach(_CMOCKA_TEST ${CMOCKA_TESTS})
-    add_cmocka_test(${_CMOCKA_TEST} ${_CMOCKA_TEST}.c ${CMOCKA_SHARED_LIBRARY})
+    add_cmocka_test(${_CMOCKA_TEST} ${_CMOCKA_TEST}.c ${CMOCKA_STATIC_LIBRARY})
 endforeach()
 
 ### Special Cases
 if (${CMAKE_C_COMPILER_ID} MATCHES "(GNU|Clang)")
     set_source_files_properties(test_cmockery.c PROPERTIES COMPILE_FLAGS "-Wno-deprecated-declarations")
 endif()
-add_cmocka_test(test_cmockery test_cmockery.c ${CMOCKA_SHARED_LIBRARY})
+add_cmocka_test(test_cmockery test_cmockery.c ${CMOCKA_STATIC_LIBRARY})
 
 ### Exceptions