diff --git a/src/include/c.h b/src/include/c.h
index 8916310..30e68ff 100644
--- a/src/include/c.h
+++ b/src/include/c.h
@@ -63,6 +63,11 @@
 #undef errcode
 #endif
 
+/* Visual Studios 2012 and earlier don't have va_copy() */
+#if _MSC_VER <= 1700
+#define va_copy(dest, src) ((dest) = (src))
+#endif
+
 /*
  * We have to include stdlib.h here because it defines many of these macros
  * on some platforms, and we only want our definitions used if stdlib.h doesn't
diff --git a/src/tools/msvc/Mkvcbuild.pm b/src/tools/msvc/Mkvcbuild.pm
index 264c530..b7182b5 100644
--- a/src/tools/msvc/Mkvcbuild.pm
+++ b/src/tools/msvc/Mkvcbuild.pm
@@ -344,7 +344,7 @@ sub mkvcbuild
 	$isolation_tester->AddDefine('HOST_TUPLE="i686-pc-win32vc"');
 	$isolation_tester->AddDefine('FRONTEND');
 	$isolation_tester->AddLibrary('wsock32.lib');
-	$isolation_tester->AddReference($libpq, $libpgport);
+	$isolation_tester->AddReference($libpq, $libpgport, $libpgcommon);
 
 	my $pgregress_isolation =
 	  $solution->AddProject('pg_isolation_regress', 'exe', 'misc');