diff --git a/CMakeLists.txt b/CMakeLists.txt
index ebd1ee50..88f55d25 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -91,11 +91,15 @@ IF (CARES_SYMBOL_HIDING)
 	CMAKE_POLICY (SET CMP0063 NEW)
 ENDIF ()
 
-# Keep build organized.
-SET (CMAKE_RUNTIME_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}/${CMAKE_INSTALL_BINDIR}")
-SET (CMAKE_LIBRARY_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}/${CMAKE_INSTALL_LIBDIR}")
-SET (CMAKE_ARCHIVE_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}/${CMAKE_INSTALL_LIBDIR}")
-SET (PACKAGE_DIRECTORY ${PROJECT_BINARY_DIR}/package)
+# Keep build organized, but only if it is the top-level project.
+# CMake 3.21 or later has PROJECT_IS_TOP_LEVEL, but we aren't yet depending on
+# that version.
+IF (CMAKE_CURRENT_SOURCE_DIR STREQUAL CMAKE_SOURCE_DIR)
+	SET (CMAKE_RUNTIME_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}/${CMAKE_INSTALL_BINDIR}")
+	SET (CMAKE_LIBRARY_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}/${CMAKE_INSTALL_LIBDIR}")
+	SET (CMAKE_ARCHIVE_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}/${CMAKE_INSTALL_LIBDIR}")
+	SET (PACKAGE_DIRECTORY ${PROJECT_BINARY_DIR}/package)
+ENDIF ()
 
 # Destinations for installing different kinds of targets (pass to install command).
 SET (TARGETS_INST_DEST