diff --git a/cmake/MatlabWrap.cmake b/cmake/MatlabWrap.cmake
index 55b7cdb..f565e8e 100644
--- a/cmake/MatlabWrap.cmake
+++ b/cmake/MatlabWrap.cmake
@@ -229,7 +229,9 @@ function(wrap_library_internal interfaceHeader moduleName linkLibraries extraInc
   if(UNIX)
     set(GTWRAP_PATH_SEPARATOR ":")
   else()
-    set(GTWRAP_PATH_SEPARATOR ";")
+    # Escaped: an unescaped ";" is CMake's list separator, so it would split
+    # the quoted PYTHONPATH argument below instead of joining two path entries.
+    set(GTWRAP_PATH_SEPARATOR "\\;")
   endif()
 
   # Set boost serialization flag for the python script call below.
diff --git a/cmake/PybindWrap.cmake b/cmake/PybindWrap.cmake
index 2c98b69..9721c8d 100644
--- a/cmake/PybindWrap.cmake
+++ b/cmake/PybindWrap.cmake
@@ -60,7 +60,9 @@ function(
   if(UNIX)
     set(GTWRAP_PATH_SEPARATOR ":")
   else()
-    set(GTWRAP_PATH_SEPARATOR ";")
+    # Escaped: an unescaped ";" is CMake's list separator, so it would split
+    # the quoted PYTHONPATH argument below instead of joining two path entries.
+    set(GTWRAP_PATH_SEPARATOR "\\;")
   endif()
 
   # Create a copy of interface_headers so we can freely manipulate it