diff --git a/Makefile.global b/Makefile.global
index 0aee5876..98b6962e 100644
--- a/Makefile.global
+++ b/Makefile.global
@@ -49,8 +49,7 @@ DETACHED_SIG_FILE=$(TAR_FILE).asc
 PV_FILE=bindings/python/notmuch/version.py
 
 # Smash together user's values with our extra values
-STD_CFLAGS := -std=gnu99
-FINAL_CFLAGS = -DNOTMUCH_VERSION=$(VERSION) $(CPPFLAGS) $(STD_CFLAGS) $(CFLAGS) $(WARN_CFLAGS) $(extra_cflags) $(CONFIGURE_CFLAGS)
+FINAL_CFLAGS = -DNOTMUCH_VERSION=$(VERSION) $(CPPFLAGS) $(CFLAGS) $(WARN_CFLAGS) $(extra_cflags) $(CONFIGURE_CFLAGS)
 FINAL_CXXFLAGS = $(CPPFLAGS) $(CXXFLAGS) $(WARN_CXXFLAGS) $(extra_cflags) $(extra_cxxflags) $(CONFIGURE_CXXFLAGS)
 FINAL_NOTMUCH_LDFLAGS = $(LDFLAGS) -Lutil -lnotmuch_util -Llib -lnotmuch
 ifeq ($(LIBDIR_IN_LDCONFIG),0)