diff --git a/.github/workflows/testing.yml b/.github/workflows/testing.yml
index b5b1c9ed..38a10939 100644
--- a/.github/workflows/testing.yml
+++ b/.github/workflows/testing.yml
@@ -383,7 +383,7 @@ jobs:
           prepare: |
             .github/scripts/install_deps.sh freebsd
           run: | # FreeBSD `c++` compiler does not support `make develop` sanitizers ASan or UBSan
-            cmake -S . -B build -DCMAKE_BUILD_TYPE=Debug -DCMAKE_CXX_COMPILER=c++ -DUSE_EXTERNAL_TESTS=OFF -DTESTS_OS_NAME=freebsd
+            cmake -S . -B build -DCMAKE_BUILD_TYPE=Debug -DCMAKE_CXX_COMPILER=c++ -DTESTS_RUN_EXTERNAL=OFF -DTESTS_OS_NAME=freebsd
             cmake --build build -j4 --verbose
             cmake --install build --verbose
             cmake --build build --target test
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 60929e4a..9749b2ca 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -8,7 +8,7 @@ project(rgbds
         DESCRIPTION "Game Boy assembly toolchain"
         HOMEPAGE_URL "https://rgbds.gbdev.io")
 
-include(CTest) # Note: must be in the top-level dir.
+include(CTest) # Note: CTest only functions properly if included from the top-level CMakeLists.
 include(GNUInstallDirs)
 
 # Reject in-source builds, as they may conflict with the Makefile.
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 6cebac57..6633128f 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -1,23 +1,8 @@
 # SPDX-License-Identifier: MIT
 
-option(USE_NONFREE_TESTS "run tests that build nonfree codebases" ON)
-option(USE_EXTERNAL_TESTS "run tests that build external codebases" ON)
-set(TESTS_OS_NAME "" CACHE STRING "skip running tests known to fail on this OS")
-
-set(ONLY_FREE)
-if(NOT USE_NONFREE_TESTS)
-  set(ONLY_FREE "--only-free")
-endif()
-
-set(ONLY_INTERNAL)
-if(NOT USE_EXTERNAL_TESTS)
-  set(ONLY_INTERNAL "--only-internal")
-endif()
-
-set(OS_NAME)
-if(NOT TESTS_OS_NAME STREQUAL "")
-  set(OS_NAME "--os" "${TESTS_OS_NAME}")
-endif()
+option(TESTS_RUN_NONFREE "Run tests that build nonfree codebases." ON)
+option(TESTS_RUN_EXTERNAL "Run tests that build external codebases." ON)
+set(TESTS_OS_NAME "" CACHE STRING "Skip running tests known to fail on this OS.")
 
 add_executable(randtilegen gfx/randtilegen.cpp)
 add_executable(rgbgfx_test gfx/rgbgfx_test.cpp)
@@ -25,8 +10,6 @@ set_target_properties(randtilegen rgbgfx_test PROPERTIES
 # hack for MSVC: no-op generator expression to stop generation of "per-configuration subdirectory"
                       RUNTIME_OUTPUT_DIRECTORY $<1:${CMAKE_CURRENT_SOURCE_DIR}/gfx>)
 
-configure_file(CTestCustom.cmake.in ${CMAKE_BINARY_DIR}/CTestCustom.cmake)
-
 foreach(TARGET randtilegen rgbgfx_test)
   if(LIBPNG_FOUND) # pkg-config
     target_include_directories(${TARGET} PRIVATE ${LIBPNG_INCLUDE_DIRS})
@@ -39,6 +22,23 @@ foreach(TARGET randtilegen rgbgfx_test)
   endif()
 endforeach()
 
+set(ONLY_FREE)
+if(NOT TESTS_RUN_NONFREE)
+  set(ONLY_FREE "--only-free")
+endif()
+
+set(ONLY_INTERNAL)
+if(NOT TESTS_RUN_EXTERNAL)
+  set(ONLY_INTERNAL "--only-internal")
+endif()
+
+set(OS_NAME)
+if(NOT TESTS_OS_NAME STREQUAL "")
+  set(OS_NAME "--os" "${TESTS_OS_NAME}")
+endif()
+
+configure_file(CTestCustom.cmake.in ${CMAKE_BINARY_DIR}/CTestCustom.cmake @ONLY)
+
 add_test(NAME all
          COMMAND ./run-tests.sh ${ONLY_FREE} ${ONLY_INTERNAL} ${OS_NAME}
          WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
diff --git a/test/CTestCustom.cmake.in b/test/CTestCustom.cmake.in
index 95465b99..292d278a 100644
--- a/test/CTestCustom.cmake.in
+++ b/test/CTestCustom.cmake.in
@@ -1 +1 @@
-set(CTEST_CUSTOM_PRE_TEST "bash -c 'cd @CMAKE_CURRENT_SOURCE_DIR@\; ./fetch-test-deps.sh @ONLY_FREE@ @ONLY_INTERNAL@'")
+set(CTEST_CUSTOM_PRE_TEST "bash -ec 'cd @CMAKE_CURRENT_SOURCE_DIR@ && ./fetch-test-deps.sh @ONLY_FREE@ @ONLY_INTERNAL@'")