diff --git a/src/frontend/Makefile.am b/src/frontend/Makefile.am
index 4eb91f9c7..b82c0f36b 100644
--- a/src/frontend/Makefile.am
+++ b/src/frontend/Makefile.am
@@ -129,6 +129,7 @@ libfte_la_SOURCES = \
     inp.h       \
     inpcom.c    \
     inpcom.h    \
+    inpc_probe.c    \
     interp.c    \
     interp.h    \
     inventory.c     \
diff --git a/visualc/sharedspice.vcxproj b/visualc/sharedspice.vcxproj
index 55f4d27ce..008b5940c 100644
--- a/visualc/sharedspice.vcxproj
+++ b/visualc/sharedspice.vcxproj
@@ -1033,6 +1033,7 @@
     <ClCompile Include="..\src\frontend\init.c" />
     <ClCompile Include="..\src\frontend\inp.c" />
     <ClCompile Include="..\src\frontend\inpcom.c" />
+    <ClCompile Include="..\src\frontend\inpc_probe.c" />
     <ClCompile Include="..\src\frontend\interp.c" />
     <ClCompile Include="..\src\frontend\inventory.c" />
     <ClCompile Include="..\src\frontend\linear.c" />
diff --git a/visualc/vngspice-fftw.vcxproj b/visualc/vngspice-fftw.vcxproj
index df5d19f42..ada1fa9ef 100644
--- a/visualc/vngspice-fftw.vcxproj
+++ b/visualc/vngspice-fftw.vcxproj
@@ -1483,6 +1483,7 @@ lib /machine:x64 /def:..\..\fftw-3.3-dll64\libfftw3-3.def /out:$(IntDir)libfftw3
     <ClCompile Include="..\src\frontend\init.c" />
     <ClCompile Include="..\src\frontend\inp.c" />
     <ClCompile Include="..\src\frontend\inpcom.c" />
+    <ClCompile Include="..\src\frontend\inpc_probe.c" />
     <ClCompile Include="..\src\frontend\interp.c" />
     <ClCompile Include="..\src\frontend\inventory.c" />
     <ClCompile Include="..\src\frontend\linear.c" />
diff --git a/visualc/vngspice.vcxproj b/visualc/vngspice.vcxproj
index 9c37b349e..155802e39 100644
--- a/visualc/vngspice.vcxproj
+++ b/visualc/vngspice.vcxproj
@@ -1492,6 +1492,7 @@
     <ClCompile Include="..\src\frontend\init.c" />
     <ClCompile Include="..\src\frontend\inp.c" />
     <ClCompile Include="..\src\frontend\inpcom.c" />
+    <ClCompile Include="..\src\frontend\inpc_probe.c" />
     <ClCompile Include="..\src\frontend\interp.c" />
     <ClCompile Include="..\src\frontend\inventory.c" />
     <ClCompile Include="..\src\frontend\linear.c" />