diff --git a/.gitignore b/.gitignore
index cbb4a5c..326971f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,5 @@
 CMakeFiles
 build
-include/catch
 tests/CMakeFiles
 tests/Debug
 *.opensdf
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 5306e85..a142174 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -6,7 +6,7 @@ project(GSLTests CXX)
 set_property(GLOBAL PROPERTY USE_FOLDERS ON)
 
 list(APPEND CATCH_CMAKE_ARGS
-    "-DCMAKE_INSTALL_PREFIX=${CMAKE_SOURCE_DIR}"
+    "-DCMAKE_INSTALL_PREFIX=${CMAKE_BINARY_DIR}/external"
     "-DNO_SELFTEST=true"
 )
 
@@ -48,6 +48,11 @@ target_compile_options(gsl_tests_config INTERFACE
     >
 )
 
+# for tests to find the catch header
+target_include_directories(gsl_tests_config INTERFACE
+    ${CMAKE_BINARY_DIR}/external/include
+)
+
 # set definitions for tests
 target_compile_definitions(gsl_tests_config INTERFACE
     GSL_THROW_ON_CONTRACT_VIOLATION