diff --git a/tools/pybind11NewTools.cmake b/tools/pybind11NewTools.cmake
index 9e13daf1a..5a6a0cb8b 100644
--- a/tools/pybind11NewTools.cmake
+++ b/tools/pybind11NewTools.cmake
@@ -235,7 +235,7 @@ function(pybind11_add_module target_name)
 
   # Use case-insensitive comparison to match the result of $<CONFIG:cfgs>
   string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
-  if(NOT MSVC AND NOT ${uppercase_CMAKE_BUILD_TYPE} MATCHES DEBUG|RELWITHDEBINFO)
+  if(NOT MSVC AND NOT "${uppercase_CMAKE_BUILD_TYPE}" MATCHES DEBUG|RELWITHDEBINFO)
     # Strip unnecessary sections of the binary on Linux/macOS
     pybind11_strip(${target_name})
   endif()
diff --git a/tools/pybind11Tools.cmake b/tools/pybind11Tools.cmake
index 0dc61d399..66ad00a47 100644
--- a/tools/pybind11Tools.cmake
+++ b/tools/pybind11Tools.cmake
@@ -214,7 +214,7 @@ function(pybind11_add_module target_name)
 
   # Use case-insensitive comparison to match the result of $<CONFIG:cfgs>
   string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
-  if(NOT MSVC AND NOT ${uppercase_CMAKE_BUILD_TYPE} MATCHES DEBUG|RELWITHDEBINFO)
+  if(NOT MSVC AND NOT "${uppercase_CMAKE_BUILD_TYPE}" MATCHES DEBUG|RELWITHDEBINFO)
     pybind11_strip(${target_name})
   endif()