diff --git a/src/tools/pginclude/cpluspluscheck b/src/tools/pginclude/cpluspluscheck
index 2c5042eb41..6ad5ef6942 100755
--- a/src/tools/pginclude/cpluspluscheck
+++ b/src/tools/pginclude/cpluspluscheck
@@ -161,7 +161,31 @@ do
 	# OK, create .c file to include this .h file.
 	{
 	    echo 'extern "C" {'
-	    test "$f" != src/include/postgres_fe.h && echo '#include "postgres.h"'
+	    # Ideally we'd pre-include only the appropriate one of
+	    # postgres.h, postgres_fe.h, or c.h.  We don't always have enough
+	    # info to guess which, but in some subdirectories there's a
+	    # reasonable choice to make, and otherwise we use postgres.h.
+	    # Also, those three files should compile with no pre-include, as
+	    # should src/interfaces headers meant to be exposed to clients.
+	    case "$f" in
+		src/include/postgres.h) ;;
+		src/include/postgres_fe.h) ;;
+		src/include/c.h) ;;
+		src/interfaces/libpq/libpq-fe.h) ;;
+		src/interfaces/libpq/libpq-events.h) ;;
+		src/interfaces/ecpg/ecpglib/ecpglib_extern.h)
+		    echo '#include "postgres_fe.h"' ;;
+		src/interfaces/ecpg/ecpglib/*) ;;
+		src/interfaces/*)
+		    echo '#include "postgres_fe.h"' ;;
+		src/bin/*)
+		    echo '#include "postgres_fe.h"' ;;
+		src/port/*) ;;
+		src/common/*)
+		    echo '#include "c.h"' ;;
+		*)
+		    echo '#include "postgres.h"' ;;
+	    esac
 	    echo "#include \"$f\""
 	    echo '};'
 	} >$tmp/test.cpp
diff --git a/src/tools/pginclude/headerscheck b/src/tools/pginclude/headerscheck
index abbba7aa63..f1810c09bb 100755
--- a/src/tools/pginclude/headerscheck
+++ b/src/tools/pginclude/headerscheck
@@ -142,7 +142,31 @@ do
 
 	# OK, create .c file to include this .h file.
 	{
-	    test "$f" != src/include/postgres_fe.h && echo '#include "postgres.h"'
+	    # Ideally we'd pre-include only the appropriate one of
+	    # postgres.h, postgres_fe.h, or c.h.  We don't always have enough
+	    # info to guess which, but in some subdirectories there's a
+	    # reasonable choice to make, and otherwise we use postgres.h.
+	    # Also, those three files should compile with no pre-include, as
+	    # should src/interfaces headers meant to be exposed to clients.
+	    case "$f" in
+		src/include/postgres.h) ;;
+		src/include/postgres_fe.h) ;;
+		src/include/c.h) ;;
+		src/interfaces/libpq/libpq-fe.h) ;;
+		src/interfaces/libpq/libpq-events.h) ;;
+		src/interfaces/ecpg/ecpglib/ecpglib_extern.h)
+		    echo '#include "postgres_fe.h"' ;;
+		src/interfaces/ecpg/ecpglib/*) ;;
+		src/interfaces/*)
+		    echo '#include "postgres_fe.h"' ;;
+		src/bin/*)
+		    echo '#include "postgres_fe.h"' ;;
+		src/port/*) ;;
+		src/common/*)
+		    echo '#include "c.h"' ;;
+		*)
+		    echo '#include "postgres.h"' ;;
+	    esac
 	    echo "#include \"$f\""
 	} >$tmp/test.c