diff --git a/visualc/sharedspice.vcxproj b/visualc/sharedspice.vcxproj
index bfa3b6c24..253de5d0e 100644
--- a/visualc/sharedspice.vcxproj
+++ b/visualc/sharedspice.vcxproj
@@ -1240,6 +1240,7 @@
     <ClCompile Include="..\src\spicelib\analysis\ninteg.c" />
     <ClCompile Include="..\src\spicelib\analysis\noisean.c" />
     <ClCompile Include="..\src\spicelib\analysis\nsetparm.c" />
+    <ClCompile Include="..\src\spicelib\analysis\optran.c" />
     <ClCompile Include="..\src\spicelib\analysis\pssaskq.c" />
     <ClCompile Include="..\src\spicelib\analysis\pssinit.c" />
     <ClCompile Include="..\src\spicelib\analysis\psssetp.c" />
diff --git a/visualc/vngspice-fftw.vcxproj b/visualc/vngspice-fftw.vcxproj
index dfb7ef709..ea9f6c198 100644
--- a/visualc/vngspice-fftw.vcxproj
+++ b/visualc/vngspice-fftw.vcxproj
@@ -1694,6 +1694,7 @@ lib /machine:x64 /def:..\..\fftw-3.3-dll64\libfftw3-3.def /out:$(IntDir)libfftw3
     <ClCompile Include="..\src\spicelib\analysis\ninteg.c" />
     <ClCompile Include="..\src\spicelib\analysis\noisean.c" />
     <ClCompile Include="..\src\spicelib\analysis\nsetparm.c" />
+    <ClCompile Include="..\src\spicelib\analysis\optran.c" />
     <ClCompile Include="..\src\spicelib\analysis\pssaskq.c" />
     <ClCompile Include="..\src\spicelib\analysis\pssinit.c" />
     <ClCompile Include="..\src\spicelib\analysis\psssetp.c" />