diff --git a/libs/spandsp/src/libspandsp.2010.vcxproj b/libs/spandsp/src/libspandsp.2010.vcxproj
index dd5b5d97fa..bb2ae97878 100644
--- a/libs/spandsp/src/libspandsp.2010.vcxproj
+++ b/libs/spandsp/src/libspandsp.2010.vcxproj
@@ -219,6 +219,7 @@
     <ClCompile Include="t38_terminal.c" />
     <ClCompile Include="testcpuid.c" />
     <ClCompile Include="time_scale.c" />
+    <ClCompile Include="timezone.c" />
     <ClCompile Include="tone_detect.c" />
     <ClCompile Include="tone_generate.c" />
     <ClCompile Include="v17rx.c" />
@@ -288,6 +289,8 @@
     <ClInclude Include="spandsp\swept_tone.h" />
     <ClInclude Include="spandsp\t4_rx.h" />
     <ClInclude Include="spandsp\t4_tx.h" />
+    <ClInclude Include="spandsp\t4_t6_decode.h" />
+    <ClInclude Include="spandsp\t4_t6_encode.h" />
     <ClInclude Include="spandsp\t30.h" />
     <ClInclude Include="spandsp\t30_api.h" />
     <ClInclude Include="spandsp\t30_fcf.h" />