diff --git a/core/config_sanitizers.mk b/core/config_sanitizers.mk
index aa638d4..d837c6e 100644
--- a/core/config_sanitizers.mk
+++ b/core/config_sanitizers.mk
@@ -249,6 +249,13 @@
   endif
 endif
 
+# Ignore SANITIZE_TARGET_DIAG=memtag_heap without SANITIZE_TARGET=memtag_heap
+# This can happen if a condition above filters out memtag_heap from
+# my_sanitize. It is easier to handle all of these cases here centrally.
+ifneq ($(filter memtag_heap,$(my_sanitize_diag)),)
+  my_sanitize_diag := $(filter-out memtag_heap,$(my_sanitize_diag))
+endif
+
 ifneq ($(filter memtag_heap,$(my_sanitize)),)
   my_cflags += -fsanitize=memtag-heap
   my_sanitize := $(filter-out memtag_heap,$(my_sanitize))