diff --git a/tests/HostTests/modules/Libc.cpp b/tests/HostTests/modules/Libc.cpp
index c5c1d55e61..8878fa96e6 100644
--- a/tests/HostTests/modules/Libc.cpp
+++ b/tests/HostTests/modules/Libc.cpp
@@ -1,4 +1,5 @@
 #include <HostTests.h>
+#include <FlashString/Array.hpp>
 
 static int num_instances;
 
@@ -21,6 +22,54 @@ A a1 __attribute__((init_priority(990)));
 // Simple check to determine if a pointer refers to ROM
 #define isRomPtr(ptr) (uint32_t(ptr) >= 0x40000000 && uint32_t(ptr) < 0x40100000)
 
+/*
+	Format                              Exponent   Mantissa (effective bits)
+	Float32 IEEE754 single-precision    8          23 (24)
+	Float64 IEEE754 double-precision    11         52 (53)
+*/
+#define FLOAT32_TEST_MAP(XX)                                                                                           \
+	XX(0x0100'0000L, "16777216.00000000", "16777216.0")                                                                \
+	XX(-0x0100'0000L, "-16777216.00000000", "-16777216.0")                                                             \
+	XX(0x0100'0000L / 1000.0, "16777.21679687", "16777.21679687")                                                      \
+	XX(4294967040 * 10000.0, "42949668765696.00000000", "42949668765696.0")                                            \
+	XX(-4294967040, "-4294967040.00000000", "-4294967040.0")                                                           \
+	XX(std::numeric_limits<float>::infinity(), "Inf", "Inf")                                                           \
+	XX(-std::numeric_limits<float>::infinity(), "Inf", "Inf")                                                          \
+	XX(3.1415926535897932384626433, "3.14159274", "3.14159274")                                                        \
+	XX(32766.6612999999997555, "32766.66210937", "32766.66210937")                                                     \
+	XX(1.6613, "1.66129994", "1.66129994")                                                                             \
+	XX(-32766.1234, "-32766.12304687", "-32766.12304687")                                                              \
+	XX(0.0, "0.00000000", "0.0")                                                                                       \
+	XX(-0.0, "0.00000000", "0.0")                                                                                      \
+	XX(100.0, "100.00000000", "100.0")
+
+#define FLOAT64_TEST_MAP(XX)                                                                                           \
+	XX(0x0020'0000'0000'0000LL, "9007199254740992.0000000000000000", "9007199254740992.0")                             \
+	XX(-0x0020'0000'0000'0000LL, "-9007199254740992.0000000000000000", "-9007199254740992.0")                          \
+	XX(4294967040 + 1, "4294967041.0000000000000000", "4294967041.0")                                                  \
+	XX(-4294967040 - 1, "-4294967041.0000000000000000", "-4294967041.0")                                               \
+	XX(3.1415926535897932384626433, "3.1415926535897931", "3.1415926535897931")                                        \
+	XX(32766.6613, "32766.6612999999997555", "32766.6612999999997555")                                                 \
+	XX(1.6613, "1.6612999999999999", "1.6612999999999999")                                                             \
+	XX(-32766.1234, "-32766.1234000000004016", "-32766.1234000000004016")                                              \
+	XX(9223372036854775808.0, "9223372036854775808.0000000000000000", "9223372036854775808.0")                         \
+	XX(-9223372036854775808.0, "-9223372036854775808.0000000000000000", "-9223372036854775808.0")                      \
+	XX(3.4e18, "3400000000000000000.0000000000000000", "3400000000000000000.0")                                        \
+	XX((double)std::numeric_limits<int64_t>::max(), "9223372036854775808.0000000000000000", "9223372036854775808.0")   \
+	XX((double)std::numeric_limits<int64_t>::min(), "-9223372036854775808.0000000000000000", "-9223372036854775808.0")
+
+template <typename T> struct FloatTest {
+	T num;
+	PGM_P ref;
+	PGM_P str1;
+	PGM_P str2;
+};
+
+#define XX(num, str1, str2) {num, STR(num), str1, str2},
+DEFINE_FSTR_ARRAY_LOCAL(float32_tests, FloatTest<float>, FLOAT32_TEST_MAP(XX))
+DEFINE_FSTR_ARRAY_LOCAL(float64_tests, FloatTest<double>, FLOAT64_TEST_MAP(XX))
+#undef XX
+
 /*
  * Anything to do with main C/C++ libraries, startup code, etc.
  */
@@ -80,6 +129,22 @@ class LibcTest : public TestGroup
 			m_snprintf(buffer, sizeof(buffer), "%llu", 123456789123456789ULL);
 			REQUIRE_EQ(String(buffer), "123456789123456789");
 		}
+
+		TEST_CASE("Floating-point printing")
+		{
+			checkFloats(float32_tests, 8);
+			checkFloats(float64_tests, 16);
+		}
+	}
+
+	template <typename T> void checkFloats(const FSTR::Array<FloatTest<T>>& tests, int precision)
+	{
+		for(auto test : tests) {
+			Serial << test.ref << ": ";
+			CHECK_EQ(String(test.str1), String(test.num, precision));
+			CHECK_EQ(String(test.str2), String(test.num, -precision));
+			Serial << "OK" << endl;
+		}
 	}
 };