diff --git a/core/host_dalvik_java_library.mk b/core/host_dalvik_java_library.mk
index f5da638..502016b 100644
--- a/core/host_dalvik_java_library.mk
+++ b/core/host_dalvik_java_library.mk
@@ -133,7 +133,11 @@
 	@echo Building with Jack: $@
 	$(jack-java-to-dex)
 
+# The empty command was added because, without it, make misses the fact the $(built_dex) also
+# change $(full_classes_jack). Looks like it would test the date before running $(built_dex)
+# command.
 $(full_classes_jack): $(built_dex)
+	@echo
 
 $(LOCAL_BUILT_MODULE): PRIVATE_DEX_FILE := $(built_dex)
 $(LOCAL_BUILT_MODULE): $(built_dex) $(java_resource_sources)
diff --git a/core/java.mk b/core/java.mk
index d4f0039..4725fd4 100644
--- a/core/java.mk
+++ b/core/java.mk
@@ -610,7 +610,12 @@
 	@echo Building with Jack: $@
 	$(jack-java-to-dex)
 
+# The empty command was added because, without it, make misses the fact the $(built_dex) also
+# change $(full_classes_jack). Looks like it would test the date before running $(built_dex)
+# command.
 $(full_classes_jack): $(built_dex_intermediate)
+	@echo
+
 # nothing to do it's built as a side effect of $(built_dex_intermediate)
 endif #LOCAL_IS_STATIC_JAVA_LIBRARY