diff --git a/tests/libc_logging_test.cpp b/tests/libc_logging_test.cpp
index d9c615e..5b10ce3 100644
--- a/tests/libc_logging_test.cpp
+++ b/tests/libc_logging_test.cpp
@@ -53,10 +53,10 @@
   __libc_format_buffer(buf, sizeof(buf), "a%db", -8123);
   EXPECT_STREQ("a-8123b", buf);
 
-  __libc_format_buffer(buf, sizeof(buf), "a%hdb", 0x7fff0010);
+  __libc_format_buffer(buf, sizeof(buf), "a%hdb", static_cast<short>(0x7fff0010));
   EXPECT_STREQ("a16b", buf);
 
-  __libc_format_buffer(buf, sizeof(buf), "a%hhdb", 0x7fffff10);
+  __libc_format_buffer(buf, sizeof(buf), "a%hhdb", static_cast<char>(0x7fffff10));
   EXPECT_STREQ("a16b", buf);
 
   __libc_format_buffer(buf, sizeof(buf), "a%lldb", 0x1000000000LL);
diff --git a/tests/stack_unwinding_test_impl.c b/tests/stack_unwinding_test_impl.c
index b0099f0..7518a2c 100644
--- a/tests/stack_unwinding_test_impl.c
+++ b/tests/stack_unwinding_test_impl.c
@@ -48,7 +48,7 @@
 }
 
 static void noinline foo() {
-  char c1 __attribute__((cleanup(foo_cleanup)));
+  char c1 __attribute__((cleanup(foo_cleanup))) unused;
   do_crash();
 }
 
diff --git a/tests/stdio_test.cpp b/tests/stdio_test.cpp
index 8eb65a6..e47f967 100644
--- a/tests/stdio_test.cpp
+++ b/tests/stdio_test.cpp
@@ -226,10 +226,10 @@
   snprintf(buf, sizeof(buf), "a%db", -8123);
   EXPECT_STREQ("a-8123b", buf);
 
-  snprintf(buf, sizeof(buf), "a%hdb", 0x7fff0010);
+  snprintf(buf, sizeof(buf), "a%hdb", static_cast<short>(0x7fff0010));
   EXPECT_STREQ("a16b", buf);
 
-  snprintf(buf, sizeof(buf), "a%hhdb", 0x7fffff10);
+  snprintf(buf, sizeof(buf), "a%hhdb", static_cast<char>(0x7fffff10));
   EXPECT_STREQ("a16b", buf);
 
   snprintf(buf, sizeof(buf), "a%lldb", 0x1000000000LL);
@@ -281,7 +281,7 @@
   snprintf(buf, sizeof(buf), "a_%f_b", 1.23f);
   EXPECT_STREQ("a_1.230000_b", buf);
 
-  snprintf(buf, sizeof(buf), "a_%g_b", 3.14d);
+  snprintf(buf, sizeof(buf), "a_%g_b", 3.14);
   EXPECT_STREQ("a_3.14_b", buf);
 }