diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 3438b07..5a2825c 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -13,11 +13,11 @@ jobs:
     runs-on: ${{ matrix.os }}
     steps:
     - uses: actions/checkout@v3
-    - run: make -C tests EXTRA_CFLAGS="-W -Wall -Wextra -Wswitch-default"
+    - run: make -C tests CFLAGS="-W -Wall -Wextra -Wswitch-default"
     - run: make -C tests clean ; make -C tests pedantic
-    - run: make -C tests clean ; make -C tests pedantic EXTRA_CFLAGS=-DNO_DECLTYPE
+    - run: make -C tests clean ; make -C tests pedantic CFLAGS=-DNO_DECLTYPE
     - run: make -C tests clean ; make -C tests cplusplus
-    - run: make -C tests clean ; make -C tests cplusplus EXTRA_CFLAGS=-DNO_DECLTYPE
+    - run: make -C tests clean ; make -C tests cplusplus CFLAGS=-DNO_DECLTYPE
   build-clang:
     strategy:
       matrix:
@@ -28,11 +28,11 @@ jobs:
       CXX: clang++
     steps:
     - uses: actions/checkout@v3
-    - run: make -C tests EXTRA_CFLAGS="-W -Wall -Wextra -Wswitch-default"
+    - run: make -C tests CFLAGS="-W -Wall -Wextra -Wswitch-default"
     - run: make -C tests clean ; make -C tests pedantic
-    - run: make -C tests clean ; make -C tests pedantic EXTRA_CFLAGS=-DNO_DECLTYPE
+    - run: make -C tests clean ; make -C tests pedantic CFLAGS=-DNO_DECLTYPE
     - run: make -C tests clean ; make -C tests cplusplus
-    - run: make -C tests clean ; make -C tests cplusplus EXTRA_CFLAGS=-DNO_DECLTYPE
+    - run: make -C tests clean ; make -C tests cplusplus CFLAGS=-DNO_DECLTYPE
   build-asciidoc:
     runs-on: ubuntu-latest
     steps:
diff --git a/.travis.yml b/.travis.yml
index 6264694..346b401 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -7,8 +7,8 @@ matrix:
     compiler: clang
   - os: osx
 script:
-- make -C tests EXTRA_CFLAGS="-W -Wall -Wextra -Wswitch-default"
+- make -C tests CFLAGS="-W -Wall -Wextra -Wswitch-default"
 - make -C tests clean ; make -C tests pedantic
-- make -C tests clean ; make -C tests pedantic EXTRA_CFLAGS=-DNO_DECLTYPE
+- make -C tests clean ; make -C tests pedantic CFLAGS=-DNO_DECLTYPE
 - make -C tests clean ; make -C tests cplusplus
-- make -C tests clean ; make -C tests cplusplus EXTRA_CFLAGS=-DNO_DECLTYPE
+- make -C tests clean ; make -C tests cplusplus CFLAGS=-DNO_DECLTYPE
diff --git a/tests/Makefile b/tests/Makefile
index 1eca2d5..1de67c0 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -14,22 +14,21 @@ PROGS = test1 test2 test3 test4 test5 test6 test7 test8 test9   \
         test82 test83 test84 test85 test86 test87 test88 test89 \
         test90 test91 test92 test93 test94 test95 test96 test97 \
         test98
-CFLAGS += -I$(HASHDIR)
-#CFLAGS += -DHASH_BLOOM=16
-#CFLAGS += -O2
-CFLAGS += -g
-#CFLAGS += -Wstrict-aliasing=2
-CFLAGS += -Wall
-#CFLAGS += -Wextra
-#CFLAGS += -std=c89
-CFLAGS += ${EXTRA_CFLAGS}
+TEST_CFLAGS = -I$(HASHDIR)
+TEST_CFLAGS += -g
+#TEST_CFLAGS += -DHASH_BLOOM=16
+#TEST_CFLAGS += -O2
+TEST_CFLAGS += -Wall
+#TEST_CFLAGS += -Wstrict-aliasing=2
+#TEST_CFLAGS += -Wextra
+#TEST_CFLAGS += -std=c89
 
 ifeq ($(HASH_DEBUG),1)
-CFLAGS += -DHASH_DEBUG=1
+TEST_CFLAGS += -DHASH_DEBUG=1
 endif
 
 ifeq ($(HASH_PEDANTIC),1)
-CFLAGS += -pedantic
+TEST_CFLAGS += -pedantic
 endif
 
 TEST_TARGET=run_tests
@@ -75,35 +74,35 @@ cplusplus:
 	CC="$(CXX) -x c++" $(MAKE) all
 
 thorough:
-	$(MAKE) clean && $(MAKE) all EXTRA_CFLAGS='-pedantic'
-	$(MAKE) clean && $(MAKE) all EXTRA_CFLAGS='-pedantic -DHASH_BLOOM=16'
-	$(MAKE) clean && $(MAKE) tests_only EXTRA_CFLAGS='-pedantic -DHASH_BLOOM=16 -DHASH_DEBUG -DNO_DECLTYPE'
-	$(MAKE) clean && CC="$(CXX) -x c++" $(MAKE) all EXTRA_CFLAGS='-pedantic'
-	$(MAKE) clean && CC="$(CXX) -x c++" $(MAKE) all EXTRA_CFLAGS='-pedantic -DHASH_BLOOM=16'
-	$(MAKE) clean && CC="$(CXX) -x c++" $(MAKE) tests_only EXTRA_CFLAGS='-pedantic -DHASH_BLOOM=16 -DHASH_DEBUG -DNO_DECLTYPE'
+	$(MAKE) clean && $(MAKE) all CFLAGS="${CFLAGS} -pedantic"
+	$(MAKE) clean && $(MAKE) all CFLAGS="${CFLAGS} -pedantic -DHASH_BLOOM=16"
+	$(MAKE) clean && $(MAKE) tests_only CFLAGS="${CFLAGS} -pedantic -DHASH_BLOOM=16 -DHASH_DEBUG -DNO_DECLTYPE"
+	$(MAKE) clean && CC="$(CXX) -x c++" $(MAKE) all CFLAGS="${CFLAGS} -pedantic"
+	$(MAKE) clean && CC="$(CXX) -x c++" $(MAKE) all CFLAGS="${CFLAGS} -pedantic -DHASH_BLOOM=16"
+	$(MAKE) clean && CC="$(CXX) -x c++" $(MAKE) tests_only CFLAGS="${CFLAGS} -pedantic -DHASH_BLOOM=16 -DHASH_DEBUG -DNO_DECLTYPE"
 
 example: example.c $(HASHDIR)/uthash.h
-	$(CC) $(CPPFLAGS) $(CFLAGS) $(LDFLAGS) -o $@ $(@).c
+	$(CC) $(TEST_CFLAGS) $(CPPFLAGS) $(CFLAGS) $(LDFLAGS) -o $@ $(@).c
 
 $(PROGS) $(UTILS) : $(HASHDIR)/uthash.h
-	$(CC) $(CPPFLAGS) $(CFLAGS) $(LDFLAGS) -o $@ $(@).c
+	$(CC) $(TEST_CFLAGS) $(CPPFLAGS) $(CFLAGS) $(LDFLAGS) -o $@ $(@).c
 	@$(MKGITIGN)
 
 hashscan : $(HASHDIR)/uthash.h
-	$(CC) $(CPPFLAGS) $(CFLAGS) $(LDFLAGS) -o $@ $(@).c
+	$(CC) $(TEST_CFLAGS) $(CPPFLAGS) $(CFLAGS) $(LDFLAGS) -o $@ $(@).c
 	@$(MKGITIGN)
 
 sleep_test : $(HASHDIR)/uthash.h
-	$(CC) $(CPPFLAGS) $(CFLAGS) -DHASH_BLOOM=16 $(LDFLAGS) -o $@ $(@).c
+	$(CC) $(TEST_CFLAGS) $(CPPFLAGS) $(CFLAGS) -DHASH_BLOOM=16 $(LDFLAGS) -o $@ $(@).c
 	@$(MKGITIGN)
 
 keystat : $(HASHDIR)/uthash.h
-	$(CC) $(CPPFLAGS) $(CFLAGS) -DHASH_FUNCTION=HASH_BER $(LDFLAGS) -o keystat.BER keystat.c
-	$(CC) $(CPPFLAGS) $(CFLAGS) -DHASH_FUNCTION=HASH_FNV $(LDFLAGS) -o keystat.FNV keystat.c
-	$(CC) $(CPPFLAGS) $(CFLAGS) -DHASH_FUNCTION=HASH_JEN $(LDFLAGS) -o keystat.JEN keystat.c
-	$(CC) $(CPPFLAGS) $(CFLAGS) -DHASH_FUNCTION=HASH_OAT $(LDFLAGS) -o keystat.OAT keystat.c
-	$(CC) $(CPPFLAGS) $(CFLAGS) -DHASH_FUNCTION=HASH_SAX $(LDFLAGS) -o keystat.SAX keystat.c
-	$(CC) $(CPPFLAGS) $(CFLAGS) -DHASH_FUNCTION=HASH_SFH $(LDFLAGS) -o keystat.SFH keystat.c
+	$(CC) $(TEST_CFLAGS) $(CPPFLAGS) $(CFLAGS) -DHASH_FUNCTION=HASH_BER $(LDFLAGS) -o keystat.BER keystat.c
+	$(CC) $(TEST_CFLAGS) $(CPPFLAGS) $(CFLAGS) -DHASH_FUNCTION=HASH_FNV $(LDFLAGS) -o keystat.FNV keystat.c
+	$(CC) $(TEST_CFLAGS) $(CPPFLAGS) $(CFLAGS) -DHASH_FUNCTION=HASH_JEN $(LDFLAGS) -o keystat.JEN keystat.c
+	$(CC) $(TEST_CFLAGS) $(CPPFLAGS) $(CFLAGS) -DHASH_FUNCTION=HASH_OAT $(LDFLAGS) -o keystat.OAT keystat.c
+	$(CC) $(TEST_CFLAGS) $(CPPFLAGS) $(CFLAGS) -DHASH_FUNCTION=HASH_SAX $(LDFLAGS) -o keystat.SAX keystat.c
+	$(CC) $(TEST_CFLAGS) $(CPPFLAGS) $(CFLAGS) -DHASH_FUNCTION=HASH_SFH $(LDFLAGS) -o keystat.SFH keystat.c
 
 run_tests: $(PROGS)
 	perl $(TESTS)
diff --git a/tests/README b/tests/README
index 747661d..10f9043 100644
--- a/tests/README
+++ b/tests/README
@@ -110,8 +110,8 @@ example:   builds the 'example' program from the user guide
 
 Testing a specific hash function
 --------------------------------
-Set EXTRA_CFLAGS with this Makefile to use a specific hash function:
-   EXTRA_CFLAGS=-DHASH_FUNCTION=HASH_BER make
+Set CFLAGS with this Makefile to use a specific hash function:
+   CFLAGS=-DHASH_FUNCTION=HASH_BER make
 
 Other files
 ================================================================================
diff --git a/tests/all_funcs b/tests/all_funcs
index f61a410..9a32e24 100755
--- a/tests/all_funcs
+++ b/tests/all_funcs
@@ -5,9 +5,9 @@ function proceed {
   if [ "$response" != "y" ]; then exit -1; fi
 }
 
-make clean tests_only EXTRA_CFLAGS='-DHASH_FUNCTION=HASH_BER'; proceed
-make clean tests_only EXTRA_CFLAGS='-DHASH_FUNCTION=HASH_FNV'; proceed
-make clean tests_only EXTRA_CFLAGS='-DHASH_FUNCTION=HASH_JEN'; proceed
-make clean tests_only EXTRA_CFLAGS='-DHASH_FUNCTION=HASH_OAT'; proceed
-make clean tests_only EXTRA_CFLAGS='-DHASH_FUNCTION=HASH_SAX'; proceed
-make clean tests_only EXTRA_CFLAGS='-DHASH_FUNCTION=HASH_SFH'; proceed
+make clean tests_only CFLAGS='-DHASH_FUNCTION=HASH_BER'; proceed
+make clean tests_only CFLAGS='-DHASH_FUNCTION=HASH_FNV'; proceed
+make clean tests_only CFLAGS='-DHASH_FUNCTION=HASH_JEN'; proceed
+make clean tests_only CFLAGS='-DHASH_FUNCTION=HASH_OAT'; proceed
+make clean tests_only CFLAGS='-DHASH_FUNCTION=HASH_SAX'; proceed
+make clean tests_only CFLAGS='-DHASH_FUNCTION=HASH_SFH'; proceed