diff --git a/config-unix.mk b/config-unix.mk
index 494e60de..50695d75 100644
--- a/config-unix.mk
+++ b/config-unix.mk
@@ -80,6 +80,8 @@ endif
 
 ifeq (darwin,$(PLATFORM))
 HAVE_DTRACE=1
+# dtrace(1) probes contain dollar signs.
+CFLAGS += -Wno-dollar-in-identifier-extension
 CPPFLAGS += -D_DARWIN_USE_64_BIT_INODE=1
 LDFLAGS += -framework Foundation \
            -framework CoreServices \