diff --git a/build-config.in b/build-config.in
index f7c9e4554..c5769a7aa 100644
--- a/build-config.in
+++ b/build-config.in
@@ -118,6 +118,7 @@ USER_CPPFLAGS = @USER_CPPFLAGS@
 USER_CXXFLAGS = @USER_CXXFLAGS@
 USER_CFLAGS = @USER_CFLAGS@
 USER_LDFLAGS = @USER_LDFLAGS@
+UTF8CPP_INTERNAL = @UTF8CPP_INTERNAL@
 VORBIS_LIBS = @VORBIS_LIBS@
 WLOGICAL_OP = @WLOGICAL_OP@
 WNO_INCONSISTENT_MISSING_OVERRIDE = @WNO_INCONSISTENT_MISSING_OVERRIDE@