diff --git a/win32/libcoap.vcxproj b/win32/libcoap.vcxproj
index 72d2ccd6..4ed30cf7 100644
--- a/win32/libcoap.vcxproj
+++ b/win32/libcoap.vcxproj
@@ -43,6 +43,7 @@
     <ClCompile Include="..\src\coap_hashkey.c" />
     <ClCompile Include="..\src\coap_gnutls.c" />
     <ClCompile Include="..\src\coap_io.c" />
+    <ClCompile Include="..\src\coap_mbedtls.c" />
     <ClCompile Include="..\src\coap_notls.c" />
     <ClCompile Include="..\src\coap_openssl.c" />
     <ClCompile Include="..\src\coap_session.c" />
diff --git a/win32/libcoap.vcxproj.filters b/win32/libcoap.vcxproj.filters
index 8ae545fc..47905b83 100644
--- a/win32/libcoap.vcxproj.filters
+++ b/win32/libcoap.vcxproj.filters
@@ -39,6 +39,9 @@
     <ClCompile Include="..\src\coap_io.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\src\coap_mbedtls.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="..\src\coap_notls.c">
       <Filter>Source Files</Filter>
     </ClCompile>