diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index f3100bee..f18c23d4 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -454,8 +454,7 @@ jobs:
           TESTFLAGS="$TESTFLAGS --valgrind --context=1024 -Gdefault -Pnone" \
             make test
 
-  # test that compilation is warning free under clang
-  # run with Clang, mostly to check for Clang-specific warnings
+  # compile/run with Clang, mostly to check for Clang-specific warnings
   test-clang:
     runs-on: ubuntu-latest
     steps:
@@ -469,12 +468,8 @@ jobs:
           python3 --version
       - name: test-clang
         run: |
-          # override CFLAGS since Clang does not support -fcallgraph-info
-          # and -ftrack-macro-expansions
-          make \
-            CC=clang \
-            CFLAGS="$CFLAGS -MMD -g3 -I. -std=c99 -Wall -Wextra -pedantic" \
-            test
+          CC=clang \
+            make test
 
   # run benchmarks
   #
diff --git a/Makefile b/Makefile
index 51e9f98e..588e095d 100644
--- a/Makefile
+++ b/Makefile
@@ -18,6 +18,12 @@ VALGRIND ?= valgrind
 GDB		 ?= gdb
 PERF	 ?= perf
 
+# guess clang or gcc (clang sometimes masquerades as gcc because of
+# course it does)
+ifneq ($(shell $(CC) --version | grep clang),)
+NO_GCC = 1
+endif
+
 SRC  ?= $(filter-out $(wildcard *.t.* *.b.*),$(wildcard *.c))
 OBJ  := $(SRC:%.c=$(BUILDDIR)/%.o)
 DEP  := $(SRC:%.c=$(BUILDDIR)/%.d)
@@ -59,12 +65,15 @@ BENCH_PERF  := $(BENCH_RUNNER:%=%.perf)
 BENCH_TRACE := $(BENCH_RUNNER:%=%.trace)
 BENCH_CSV   := $(BENCH_RUNNER:%=%.csv)
 
-CFLAGS += -fcallgraph-info=su
 CFLAGS += -g3
 CFLAGS += -I.
 CFLAGS += -std=c99 -Wall -Wextra -pedantic
 CFLAGS += -Wmissing-prototypes
+ifndef NO_GCC
+CFLAGS += -fcallgraph-info=su
 CFLAGS += -ftrack-macro-expansion=0
+endif
+
 ifdef DEBUG
 CFLAGS += -O0
 else