diff --git a/core/definitions.mk b/core/definitions.mk
index f6f5840..d3d9928 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -2326,9 +2326,9 @@
     $(addprefix --classpath ,$(strip \
         $(call normalize-path-list,$(PRIVATE_ALL_JAVA_HEADER_LIBRARIES)))) \
     || ( rm -rf $(dir $@)/classes-turbine ; exit 41 ) && \
-    $(MERGE_ZIPS) -j -stripDir META-INF $@.tmp $@.premerged $(call reverse-list,$(PRIVATE_STATIC_JAVA_HEADER_LIBRARIES)) ; \
+    $(MERGE_ZIPS) -j --ignore-duplicates -stripDir META-INF $@.tmp $@.premerged $(call reverse-list,$(PRIVATE_STATIC_JAVA_HEADER_LIBRARIES)) ; \
 else \
-    $(MERGE_ZIPS) -j -stripDir META-INF $@.tmp $(call reverse-list,$(PRIVATE_STATIC_JAVA_HEADER_LIBRARIES)) ; \
+    $(MERGE_ZIPS) -j --ignore-duplicates -stripDir META-INF $@.tmp $(call reverse-list,$(PRIVATE_STATIC_JAVA_HEADER_LIBRARIES)) ; \
 fi
 $(hide) $(ZIPTIME) $@.tmp
 $(hide) $(call commit-change-for-toc,$@)