diff --git a/abclib.dsp b/abclib.dsp
index 5b4969d69..2f248c9e4 100644
--- a/abclib.dsp
+++ b/abclib.dsp
@@ -1243,6 +1243,10 @@ SOURCE=.\src\sat\bsat\satProof.c
 # End Source File
 # Begin Source File
 
+SOURCE=.\src\sat\bsat\satProof2.h
+# End Source File
+# Begin Source File
+
 SOURCE=.\src\sat\bsat\satSolver.c
 # End Source File
 # Begin Source File