diff --git a/tests/SConstruct b/tests/SConstruct
index c100a07..2b3698d 100644
--- a/tests/SConstruct
+++ b/tests/SConstruct
@@ -14,8 +14,10 @@ LINKFLAGS   Flags to pass to linker
 LINKLIBS    Flags to pass to linker after object files
 PROTOC      Path to protoc binary
 PROTOCFLAGS Arguments to pass protoc
+PLATFORM    Run using simulator
 NODEFARGS   Do not add the default CCFLAGS
 NOVALGRIND  Do not use valgrind for memory checks
+NOUNSAFE    Skip tests that intentionally break memory safety
 
 For example, for a clang build, use:
 scons CC=clang CXX=clang++
diff --git a/tests/alltypes/decode_alltypes.c b/tests/alltypes/decode_alltypes.c
index 8e70d86..008c117 100644
--- a/tests/alltypes/decode_alltypes.c
+++ b/tests/alltypes/decode_alltypes.c
@@ -302,9 +302,6 @@ bool check_alltypes(pb_istream_t *stream, int mode)
     return status == 0;
 }
 
-#ifdef __cplusplus
-extern "C"
-#endif
 int main(int argc, char **argv)
 {
     uint8_t buffer[1024];
diff --git a/tests/alltypes/encode_alltypes.c b/tests/alltypes/encode_alltypes.c
index 6067c54..2fcb813 100644
--- a/tests/alltypes/encode_alltypes.c
+++ b/tests/alltypes/encode_alltypes.c
@@ -8,9 +8,6 @@
 #include "alltypes.pb.h"
 #include "test_helpers.h"
 
-#ifdef __cplusplus
-extern "C"
-#endif
 int main(int argc, char **argv)
 {
     int mode = (argc > 1) ? atoi(argv[1]) : 0;
diff --git a/tests/cxx_callback_datatype/cxx_callback_datatype.cpp b/tests/cxx_callback_datatype/cxx_callback_datatype.cpp
index 2b06d37..e506037 100644
--- a/tests/cxx_callback_datatype/cxx_callback_datatype.cpp
+++ b/tests/cxx_callback_datatype/cxx_callback_datatype.cpp
@@ -44,7 +44,6 @@ bool TestMessage_callback(pb_istream_t *istream, pb_ostream_t *ostream, const pb
 	return true;
 }
 
-extern "C"
 int main() {
 	TestMessage source = TestMessage_init_zero; // Not strictly necessary to initialize, just using it to test the initializer.
 	source.values.push_back(5);
diff --git a/tests/cxx_descriptor/message_descriptor.cc b/tests/cxx_descriptor/message_descriptor.cc
index 149000b..f034d85 100644
--- a/tests/cxx_descriptor/message_descriptor.cc
+++ b/tests/cxx_descriptor/message_descriptor.cc
@@ -2,7 +2,7 @@
 #include "message.pb.h"
 #include "unittests.h"
 
-extern "C" int main() {
+int main() {
   using namespace nanopb;
 
 #if __cplusplus >= 201103L
diff --git a/tests/enum_sizes/enum_intsize_unittests.cc b/tests/enum_sizes/enum_intsize_unittests.cc
index dae8737..e89d8f3 100644
--- a/tests/enum_sizes/enum_intsize_unittests.cc
+++ b/tests/enum_sizes/enum_intsize_unittests.cc
@@ -2,7 +2,7 @@
 #include "enum_intsize.pb.hpp"
 #include "unittests.h"
 
-extern "C" int main()
+int main()
 {
   int status = 0;
 
diff --git a/tests/namingstyle/test_cxx_descriptor.cc b/tests/namingstyle/test_cxx_descriptor.cc
index ff69df3..857f115 100644
--- a/tests/namingstyle/test_cxx_descriptor.cc
+++ b/tests/namingstyle/test_cxx_descriptor.cc
@@ -2,7 +2,7 @@
 #include "naming_style.pb.h"
 #include "unittests.h"
 
-extern "C" int main() {
+int main() {
   using namespace nanopb;
 
   int status = 0;
diff --git a/tests/regression/issue_494/oneof_size.cc b/tests/regression/issue_494/oneof_size.cc
index 608fd91..493166c 100644
--- a/tests/regression/issue_494/oneof_size.cc
+++ b/tests/regression/issue_494/oneof_size.cc
@@ -1,7 +1,7 @@
 #include "oneof.pb.h"
 #include "unittests.h"
 
-extern "C" int main()
+int main()
 {
     int status = 0;
 
diff --git a/tests/regression/issue_838/enum_to_string.cxx b/tests/regression/issue_838/enum_to_string.cxx
index 69c4b40..d1e857a 100644
--- a/tests/regression/issue_838/enum_to_string.cxx
+++ b/tests/regression/issue_838/enum_to_string.cxx
@@ -2,7 +2,7 @@
 #include "unittests.h"
 #include "enum.pb.h"
 
-extern "C" int main()
+int main()
 {
     int status = 0;
     TEST(strcmp(MyEnum_name(MyEnum_VALUE1), "VALUE1") == 0);
diff --git a/tests/site_scons/platforms/avr/avr_io.c b/tests/site_scons/platforms/avr/avr_io.c
index 30f40c1..e83e6c0 100644
--- a/tests/site_scons/platforms/avr/avr_io.c
+++ b/tests/site_scons/platforms/avr/avr_io.c
@@ -11,6 +11,10 @@
 #undef main
 extern int app_main(int argc, const char **argv);
 
+// Declare weak symbols in case the main program is compiled as C++
+__attribute__((weak)) int _Z12app_mainiPPc(int argc, const char **argv) {return 0;};
+int app_main(int argc, const char **argv) __attribute__((weak, alias("_Z12app_mainiPPc")));
+
 struct {
     uint8_t argc;
     char args[3][16];
diff --git a/tests/stackusage/SConscript b/tests/stackusage/SConscript
index a0c6669..0f092f5 100644
--- a/tests/stackusage/SConscript
+++ b/tests/stackusage/SConscript
@@ -1,7 +1,10 @@
 # Test stack usage
+# This test case intentionally performs access outside the legal stack area,
+# so it may have to be skipped to avoid false positives on memory safety tools.
 
 Import("env")
 
-env.NanopbProto(["stackusage", "stackusage.options"])
-test = env.Program(["stackusage.c", "stackusage.pb.c", "$COMMON/pb_encode.o", "$COMMON/pb_decode.o", "$COMMON/pb_common.o"])
-env.RunTest(test)
+if not env.get("NOUNSAFE"):
+    env.NanopbProto(["stackusage", "stackusage.options"])
+    test = env.Program(["stackusage.c", "stackusage.pb.c", "$COMMON/pb_encode.o", "$COMMON/pb_decode.o", "$COMMON/pb_common.o"])
+    env.RunTest(test)