diff --git a/dtool/src/dtoolbase/CMakeLists.txt b/dtool/src/dtoolbase/CMakeLists.txt
index 344dce51fd..be2cc44394 100644
--- a/dtool/src/dtoolbase/CMakeLists.txt
+++ b/dtool/src/dtoolbase/CMakeLists.txt
@@ -91,7 +91,7 @@ add_component_library(p3dtoolbase NOINIT SYMBOL BUILDING_DTOOL_DTOOLBASE
 # Help other libraries find the autogenerated headers
 target_include_directories(p3dtoolbase PUBLIC
   $<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}>
-  $<BUILD_INTERFACE:${PROJECT_BINARY_DIR}/${CMAKE_CFG_INTDIR}>/include)
+  $<BUILD_INTERFACE:${PROJECT_BINARY_DIR}/${CMAKE_CFG_INTDIR}/include>)
 target_link_libraries(p3dtoolbase PKG::EIGEN PKG::THREADS)
 target_interrogate(p3dtoolbase ${P3DTOOLBASE_SOURCES} EXTENSIONS ${P3DTOOLBASE_IGATEEXT})