diff --git a/make/testing_flags.mk b/make/testing_flags.mk
index 0eb486bab..bd4bee194 100644
--- a/make/testing_flags.mk
+++ b/make/testing_flags.mk
@@ -12,6 +12,16 @@ endif
 # If a specific unit test case is being target, construct test.run filter.
 ifneq ($(case),)
 TEST_FLAGS += -test.run=$(case)
+UNIT_TARGETED = yes
+endif
+
+# If specific package is being unit tested, construct the full name of the
+# subpackage.
+ifneq ($(pkg),)
+UNITPKG := $(PKG)/$(pkg)
+COVER_PKG := $(PKG)/$(pkg)
+UNIT_TARGETED = yes
+GOLIST = echo '$(PKG)/$(pkg)'
 endif
 
 # Add any additional tags that are passed in to make.
@@ -19,5 +29,18 @@ ifneq ($(tags),)
 DEV_TAGS += ${tags}
 endif
 
+# UNIT_TARGETED is undefined iff a specific package and/or unit test case is
+# not being targeted.
+UNIT_TARGETED ?= no
+
+# If a specific package/test case was requested, run the unit test for the
+# targeted case. Otherwise, default to running all tests.
+ifeq ($(UNIT_TARGETED), yes)
+UNIT := $(GOTEST) -tags="$(DEV_TAGS) $(COMPILE_TAGS)" $(TEST_FLAGS) $(UNITPKG)
+UNIT_RACE := $(GOTEST) -tags="$(DEV_TAGS) $(COMPILE_TAGS)" $(TEST_FLAGS) -race $(UNITPKG)
+endif
+
+ifeq ($(UNIT_TARGETED), no)
 UNIT := $(GOLIST) | $(XARGS) env $(GOTEST) -tags="$(DEV_TAGS) $(COMPILE_TAGS)" $(TEST_FLAGS)
-UNIT_RACE := $(UNIT) -race
\ No newline at end of file
+UNIT_RACE := $(UNIT) -race
+endif
\ No newline at end of file