diff --git a/cmake/asio.cmake b/cmake/asio.cmake
index 68ab97f8..52b5c7d4 100644
--- a/cmake/asio.cmake
+++ b/cmake/asio.cmake
@@ -18,6 +18,7 @@ function(download_asio)
   foreach(f IN LISTS possible_file_locations)
     if(EXISTS ${f})
       set(asio_URL  "${f}")
+      file(TO_CMAKE_PATH "${asio_URL}" asio_URL)
       set(asio_URL2)
       break()
     endif()
diff --git a/cmake/googletest.cmake b/cmake/googletest.cmake
index 2907f7c7..8be03f54 100644
--- a/cmake/googletest.cmake
+++ b/cmake/googletest.cmake
@@ -18,6 +18,7 @@ function(download_googltest)
   foreach(f IN LISTS possible_file_locations)
     if(EXISTS ${f})
       set(googletest_URL  "${f}")
+      file(TO_CMAKE_PATH "${googletest_URL}" googletest_URL)
       set(googletest_URL2)
       break()
     endif()
diff --git a/cmake/kaldi-native-fbank.cmake b/cmake/kaldi-native-fbank.cmake
index 240aae98..2246d6e2 100644
--- a/cmake/kaldi-native-fbank.cmake
+++ b/cmake/kaldi-native-fbank.cmake
@@ -22,6 +22,7 @@ function(download_kaldi_native_fbank)
   foreach(f IN LISTS possible_file_locations)
     if(EXISTS ${f})
       set(kaldi_native_fbank_URL  "${f}")
+      file(TO_CMAKE_PATH "${kaldi_native_fbank_URL}" kaldi_native_fbank_URL)
       set(kaldi_native_fbank_URL2 )
       break()
     endif()
diff --git a/cmake/onnxruntime.cmake b/cmake/onnxruntime.cmake
index b250d513..573977af 100644
--- a/cmake/onnxruntime.cmake
+++ b/cmake/onnxruntime.cmake
@@ -100,6 +100,7 @@ function(download_onnxruntime)
   foreach(f IN LISTS possible_file_locations)
     if(EXISTS ${f})
       set(onnxruntime_URL  "${f}")
+      file(TO_CMAKE_PATH "${onnxruntime_URL}" onnxruntime_URL)
       set(onnxruntime_URL2)
       break()
     endif()
diff --git a/cmake/portaudio.cmake b/cmake/portaudio.cmake
index 2b842921..7de187be 100644
--- a/cmake/portaudio.cmake
+++ b/cmake/portaudio.cmake
@@ -19,6 +19,7 @@ function(download_portaudio)
   foreach(f IN LISTS possible_file_locations)
     if(EXISTS ${f})
       set(portaudio_URL  "${f}")
+      file(TO_CMAKE_PATH "${portaudio_URL}" portaudio_URL)
       set(portaudio_URL2)
       break()
     endif()
diff --git a/cmake/pybind11.cmake b/cmake/pybind11.cmake
index 30e141ad..3b007090 100644
--- a/cmake/pybind11.cmake
+++ b/cmake/pybind11.cmake
@@ -18,6 +18,7 @@ function(download_pybind11)
   foreach(f IN LISTS possible_file_locations)
     if(EXISTS ${f})
       set(pybind11_URL  "${f}")
+      file(TO_CMAKE_PATH "${pybind11_URL}" pybind11_URL)
       set(pybind11_URL2)
       break()
     endif()
diff --git a/cmake/websocketpp.cmake b/cmake/websocketpp.cmake
index f0e6b3dd..35a052bc 100644
--- a/cmake/websocketpp.cmake
+++ b/cmake/websocketpp.cmake
@@ -19,6 +19,7 @@ function(download_websocketpp)
   foreach(f IN LISTS possible_file_locations)
     if(EXISTS ${f})
       set(websocketpp_URL  "${f}")
+      file(TO_CMAKE_PATH "${websocketpp_URL}" websocketpp_URL)
       set(websocketpp_URL2)
       break()
     endif()