diff --git a/firmware/util/efilib.h b/firmware/util/efilib.h
index fd3858e6a8..7bffa3fa72 100644
--- a/firmware/util/efilib.h
+++ b/firmware/util/efilib.h
@@ -86,6 +86,8 @@ float expf_taylor(float x);
 
 #include <cstddef>
 
+#define IS_NEGATIVE_ZERO(value) (std::signbit(value) && value==0)
+
 // C++ helpers go here
 namespace efi
 {
diff --git a/unit_tests/tests/test_util.cpp b/unit_tests/tests/test_util.cpp
index 1d312ab6d7..379d1c5690 100644
--- a/unit_tests/tests/test_util.cpp
+++ b/unit_tests/tests/test_util.cpp
@@ -28,6 +28,14 @@
 
 #include "gtest/gtest.h"
 
+TEST(util, negativeZero) {
+	ASSERT_TRUE(IS_NEGATIVE_ZERO(-0.0));
+
+	ASSERT_FALSE(IS_NEGATIVE_ZERO(-10.0));
+	ASSERT_FALSE(IS_NEGATIVE_ZERO(10.0));
+	ASSERT_FALSE(IS_NEGATIVE_ZERO(0.0));
+}
+
 TEST(util, crc) {
 	ASSERT_EQ(4, efiRound(4.4, 1));
 	ASSERT_FLOAT_EQ(1.2, efiRound(1.2345, 0.1));