diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f1d23f40fa..48a94ef984 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -83,7 +83,7 @@ jobs:
     steps:
       - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
       - name: make
-        run: make -j3 SERVER_CFLAGS='-Werror'
+        run: make -j3 all-with-unit-tests SERVER_CFLAGS='-Werror'
 
   build-32bit:
     runs-on: ubuntu-latest
diff --git a/src/Makefile b/src/Makefile
index 020b70d6d5..ae2de1c626 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -98,15 +98,6 @@ ifeq ($(USE_JEMALLOC),no)
 	MALLOC=libc
 endif
 
-# Some unit tests compile files a second time to get access to static functions, the "--allow-multiple-definition" flag
-# allows us to do that without an error, by using the first instance of function. This behavior can also be used
-# to tweak behavior of code just for unit tests. The version of ld on MacOS apparently always does this.
-ifneq ($(uname_S),Darwin)
-	ALLOW_DUPLICATE_FLAG=-Wl,--allow-multiple-definition
-else
-	ALLOW_DUPLICATE_FLAG=
-endif
-
 ifdef SANITIZER
 ifeq ($(SANITIZER),address)
 	MALLOC=libc
@@ -494,7 +485,7 @@ $(ENGINE_LIB_NAME): $(ENGINE_SERVER_OBJ)
 
 # valkey-unit-tests
 $(ENGINE_UNIT_TESTS): $(ENGINE_TEST_OBJ) $(ENGINE_LIB_NAME)
-	$(SERVER_LD) $(ALLOW_DUPLICATE_FLAG) -o $@ $^ ../deps/hiredis/libhiredis.a ../deps/lua/src/liblua.a ../deps/hdr_histogram/libhdrhistogram.a ../deps/fpconv/libfpconv.a $(FINAL_LIBS)
+	$(SERVER_LD) -o $@ $^ ../deps/hiredis/libhiredis.a ../deps/lua/src/liblua.a ../deps/hdr_histogram/libhdrhistogram.a ../deps/fpconv/libfpconv.a $(FINAL_LIBS)
 
 # valkey-sentinel
 $(ENGINE_SENTINEL_NAME): $(SERVER_NAME)
diff --git a/src/debug.c b/src/debug.c
index 98512fd436..d221a884ee 100644
--- a/src/debug.c
+++ b/src/debug.c
@@ -1023,7 +1023,7 @@ void debugCommand(client *c) {
 
 /* =========================== Crash handling  ============================== */
 
-__attribute__((noinline)) void _serverAssert(const char *estr, const char *file, int line) {
+__attribute__((noinline, weak)) void _serverAssert(const char *estr, const char *file, int line) {
     int new_report = bugReportStart();
     serverLog(LL_WARNING, "=== %sASSERTION FAILED ===", new_report ? "" : "RECURSIVE ");
     serverLog(LL_WARNING, "==> %s:%d '%s' is not true", file, line, estr);
diff --git a/src/server.c b/src/server.c
index e95012eefa..508edc7112 100644
--- a/src/server.c
+++ b/src/server.c
@@ -6810,7 +6810,8 @@ serverTestProc *getTestProcByName(const char *name) {
 }
 #endif
 
-int main(int argc, char **argv) {
+/* Main is marked as weak so that unit tests can use their own main function. */
+__attribute__((weak)) int main(int argc, char **argv) {
     struct timeval tv;
     int j;
     char config_from_stdin = 0;