diff --git a/daemon.am b/daemon.am
index 1d4d955a0c..069700b1b6 100644
--- a/daemon.am
+++ b/daemon.am
@@ -115,7 +115,7 @@ libstore_a_CPPFLAGS =				\
   -DNIX_BIN_DIR=\"$(bindir)\"			\
   -DOPENSSL_PATH="\"openssl\""
 
-libstore_a_CFLAGS =				\
+libstore_a_CXXFLAGS =				\
   $(SQLITE3_CFLAGS) $(LIBGCRYPT_CFLAGS)
 
 bin_PROGRAMS = guix-daemon