diff --git a/include/box2d/types.h b/include/box2d/types.h
index e5b7ad4a..a7052aa0 100644
--- a/include/box2d/types.h
+++ b/include/box2d/types.h
@@ -13,8 +13,10 @@
 
 #ifdef __cplusplus
 #define B2_LITERAL(T) T
+#define B2_ZERO_INIT {}
 #else
 #define B2_LITERAL(T) (T)
+#define B2_ZERO_INIT {0}
 #endif
 
 #define B2_ARRAY_COUNT(A) (int)(sizeof(A) / sizeof(A[0]))
@@ -177,7 +179,7 @@ typedef struct b2BodyDef
 {
 	/// The body type: static, kinematic, or dynamic.
 	/// Note: if a dynamic body would have zero mass, the mass is set to one.
-	enum b2BodyType type;
+	b2BodyType type;
 
 	/// The world position of the body. Avoid creating bodies at the origin
 	/// since this can lead to many overlapping shapes.
@@ -342,7 +344,7 @@ static inline b2WorldDef b2DefaultWorldDef(void)
 /// Make a body definition with default values.
 static inline b2BodyDef b2DefaultBodyDef(void)
 {
-	b2BodyDef def = {0};
+	b2BodyDef def = B2_ZERO_INIT;
 	def.type = b2_staticBody;
 	def.position = B2_LITERAL(b2Vec2){0.0f, 0.0f};
 	def.angle = 0.0f;
diff --git a/samples/CMakeLists.txt b/samples/CMakeLists.txt
index 93a601d4..e31c3180 100644
--- a/samples/CMakeLists.txt
+++ b/samples/CMakeLists.txt
@@ -12,10 +12,10 @@ add_library(
 target_include_directories(glad PUBLIC ${GLAD_DIR}/include)
 
 # glfw for windowing and input
-SET(GLFW_BUILD_DOCS OFF CACHE BOOL "GLFW Docs")
-SET(GLFW_BUILD_EXAMPLES OFF CACHE BOOL "GLFW Examples")
-SET(GLFW_BUILD_TESTS OFF CACHE BOOL "GLFW Tests")
-SET(GLFW_INSTALL OFF CACHE BOOL "GLFW Install")
+set(GLFW_BUILD_DOCS OFF CACHE BOOL "GLFW Docs")
+set(GLFW_BUILD_EXAMPLES OFF CACHE BOOL "GLFW Examples")
+set(GLFW_BUILD_TESTS OFF CACHE BOOL "GLFW Tests")
+set(GLFW_INSTALL OFF CACHE BOOL "GLFW Install")
 
 FetchContent_Declare(
 	glfw
@@ -94,6 +94,10 @@ set_target_properties(samples PROPERTIES
 target_include_directories(samples PRIVATE ${CMAKE_CURRENT_SOURCE_DIR} ${JSMN_DIR})
 target_link_libraries(samples PUBLIC box2d imgui glfw glad enkiTS)
 
+if (${CMAKE_BUILD_TYPE} STREQUAL Debug)
+	target_compile_definitions(samples PRIVATE _DEBUG)
+endif ()
+
 # message(STATUS "runtime = ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}")
 # message(STATUS "binary = ${CMAKE_CURRENT_BINARY_DIR}")
 
diff --git a/samples/collection/sample_dynamic_tree.cpp b/samples/collection/sample_dynamic_tree.cpp
index 170cb389..6e4e75f2 100644
--- a/samples/collection/sample_dynamic_tree.cpp
+++ b/samples/collection/sample_dynamic_tree.cpp
@@ -218,7 +218,7 @@ class DynamicTree : public Sample
 				m_startPoint = p;
 				m_endPoint = p;
 			}
-			else if (mods = GLFW_MOD_SHIFT && m_rayDrag == false)
+			else if (mods == GLFW_MOD_SHIFT && m_rayDrag == false)
 			{
 				m_queryDrag = true;
 				m_startPoint = p;
diff --git a/samples/main.cpp b/samples/main.cpp
index a112fbc2..a1da5c66 100644
--- a/samples/main.cpp
+++ b/samples/main.cpp
@@ -550,7 +550,7 @@ int main(int, char**)
 	// MSAA
 	glfwWindowHint(GLFW_SAMPLES, 4);
 
-	sprintf(buffer, "Box2D Version %d.%d.%d Smooth", b2_version.major, b2_version.minor, b2_version.revision);
+	snprintf(buffer, 128, "Box2D Version %d.%d.%d Smooth", b2_version.major, b2_version.minor, b2_version.revision);
 
 	if (GLFWmonitor* primaryMonitor = glfwGetPrimaryMonitor())
 	{
@@ -670,7 +670,7 @@ int main(int, char**)
 		if (g_draw.m_showUI)
 		{
 			const SampleEntry& entry = g_sampleEntries[s_settings.m_sampleIndex];
-			sprintf(buffer, "%s : %s", entry.category, entry.name);
+			snprintf(buffer, 128, "%s : %s", entry.category, entry.name);
 			s_sample->DrawTitle(buffer);
 		}
 
@@ -684,13 +684,13 @@ int main(int, char**)
 
 		// if (g_draw.m_showUI)
 		{
-			sprintf(buffer, "%.1f ms", 1000.0f * frameTime);
+			snprintf(buffer, 128, "%.1f ms", 1000.0f * frameTime);
 
 			ImGui::Begin("Overlay", nullptr,
 						ImGuiWindowFlags_NoTitleBar | ImGuiWindowFlags_NoInputs | ImGuiWindowFlags_AlwaysAutoResize |
 							ImGuiWindowFlags_NoScrollbar);
 			ImGui::SetCursorPos(ImVec2(5.0f, g_camera.m_height - 20.0f));
-			ImGui::TextColored(ImColor(153, 230, 153, 255), buffer);
+			ImGui::TextColored(ImColor(153, 230, 153, 255), "%s", buffer);
 			ImGui::End();
 		}
 
diff --git a/samples/sample.cpp b/samples/sample.cpp
index b82c02db..89d71a5c 100644
--- a/samples/sample.cpp
+++ b/samples/sample.cpp
@@ -279,14 +279,14 @@ void Sample::Step(Settings& settings)
 
 		int32_t totalCount = 0;
 		char buffer[256] = {0};
-		int32_t offset = sprintf_s(buffer, 256, "colors: ");
+		int32_t offset = snprintf(buffer, 256, "colors: ");
 		for (int32_t i = 0; i < b2_graphColorCount; ++i)
 		{
-			offset += sprintf_s(buffer + offset, 256 - offset, "%d/", s.colorCounts[i]);
+			offset += snprintf(buffer + offset, 256 - offset, "%d/", s.colorCounts[i]);
 			totalCount += s.colorCounts[i];
 		}
 		totalCount += s.colorCounts[b2_graphColorCount];
-		sprintf_s(buffer + offset, 256 - offset, "(%d)[%d]", s.colorCounts[b2_graphColorCount], totalCount);
+		snprintf(buffer + offset, 256 - offset, "(%d)[%d]", s.colorCounts[b2_graphColorCount], totalCount);
 		g_draw.DrawString(5, m_textLine, buffer);
 		m_textLine += m_textIncrement;
 
diff --git a/samples/sample.h b/samples/sample.h
index 758ebdb9..2f92f146 100644
--- a/samples/sample.h
+++ b/samples/sample.h
@@ -17,7 +17,7 @@
 
 struct Settings;
 
-#ifdef _DEBUG
+#if defined(_DEBUG)
 constexpr bool g_sampleDebug = true;
 #else
 constexpr bool g_sampleDebug = false;
diff --git a/samples/settings.cpp b/samples/settings.cpp
index 42d4fcbb..c5541041 100644
--- a/samples/settings.cpp
+++ b/samples/settings.cpp
@@ -100,7 +100,7 @@ void Settings::Load()
 			int count = tokens[i + 1].end - tokens[i + 1].start;
 			assert(count < 32);
 			const char* s = data + tokens[i + 1].start;
-			strncpy_s(buffer, 32, s, count);
+			strncpy(buffer, s, count);
 			char* dummy;
 			m_sampleIndex = strtol(buffer, &dummy, 10);
 		}
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 0f6f47d4..fa3a5de0 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -90,7 +90,7 @@ message(STATUS "CMake C compiler: ${CMAKE_C_COMPILER_ID}")
 message(STATUS "CMake C++ compiler: ${CMAKE_CXX_COMPILER_ID}")
 message(STATUS "CMake system name: ${CMAKE_SYSTEM_NAME}")
 
-if ("${CMAKE_SYSTEM_NAME}" STREQUAL "Windows")
+if (MSVC)
 	if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
 		# target_compile_options(box2d PRIVATE /W4 /WX)
 		target_compile_options(box2d PRIVATE /W4 /WX /experimental:c11atomics)
@@ -101,9 +101,12 @@ if ("${CMAKE_SYSTEM_NAME}" STREQUAL "Windows")
 		message(STATUS "CMake using Clang-CL")
 		target_compile_options(box2d PRIVATE /W4 /WX /std:c17 /arch:AVX2)
 	endif()
-else()
+elseif(LINUX)
 	# FMA -mfma
 	target_compile_options(box2d PRIVATE -Wall -Wextra -Wpedantic -Werror -mavx)
+elseif(APPLE)
+	# enkiTS has some missing (void) on functions
+	target_compile_options(box2d PRIVATE -Wall -Wextra -Wpedantic -Werror -Wno-strict-prototypes)
 endif()
 
 find_library(MATH_LIBRARY m)
diff --git a/src/contact_solver.c b/src/contact_solver.c
index 2c5f22e0..bd898c08 100644
--- a/src/contact_solver.c
+++ b/src/contact_solver.c
@@ -11,8 +11,8 @@
 #include "world.h"
 
 // #include <immintrin.h>
-#include <x86/avx2.h>
-#include <x86/fma.h>
+#include "x86/avx2.h"
+#include "x86/fma.h"
 
 // Soft constraints with constraint error substepping. Includes a bias removal stage to help remove excess energy.
 // http://mmacklin.com/smallsteps.pdf
@@ -435,14 +435,14 @@ static b2SimdBody b2GatherBodies(const b2SolverBody* restrict bodies, int32_t* r
 	b2FloatW t5 = simde_mm256_unpackhi_ps(b4, b5);
 	b2FloatW t6 = simde_mm256_unpacklo_ps(b6, b7);
 	b2FloatW t7 = simde_mm256_unpackhi_ps(b6, b7);
-	b2FloatW tt0 = simde_mm256_shuffle_ps(t0, t2, _MM_SHUFFLE(1, 0, 1, 0));
-	b2FloatW tt1 = simde_mm256_shuffle_ps(t0, t2, _MM_SHUFFLE(3, 2, 3, 2));
-	b2FloatW tt2 = simde_mm256_shuffle_ps(t1, t3, _MM_SHUFFLE(1, 0, 1, 0));
-	b2FloatW tt3 = simde_mm256_shuffle_ps(t1, t3, _MM_SHUFFLE(3, 2, 3, 2));
-	b2FloatW tt4 = simde_mm256_shuffle_ps(t4, t6, _MM_SHUFFLE(1, 0, 1, 0));
-	b2FloatW tt5 = simde_mm256_shuffle_ps(t4, t6, _MM_SHUFFLE(3, 2, 3, 2));
-	b2FloatW tt6 = simde_mm256_shuffle_ps(t5, t7, _MM_SHUFFLE(1, 0, 1, 0));
-	b2FloatW tt7 = simde_mm256_shuffle_ps(t5, t7, _MM_SHUFFLE(3, 2, 3, 2));
+	b2FloatW tt0 = simde_mm256_shuffle_ps(t0, t2, SIMDE_MM_SHUFFLE(1, 0, 1, 0));
+	b2FloatW tt1 = simde_mm256_shuffle_ps(t0, t2, SIMDE_MM_SHUFFLE(3, 2, 3, 2));
+	b2FloatW tt2 = simde_mm256_shuffle_ps(t1, t3, SIMDE_MM_SHUFFLE(1, 0, 1, 0));
+	b2FloatW tt3 = simde_mm256_shuffle_ps(t1, t3, SIMDE_MM_SHUFFLE(3, 2, 3, 2));
+	b2FloatW tt4 = simde_mm256_shuffle_ps(t4, t6, SIMDE_MM_SHUFFLE(1, 0, 1, 0));
+	b2FloatW tt5 = simde_mm256_shuffle_ps(t4, t6, SIMDE_MM_SHUFFLE(3, 2, 3, 2));
+	b2FloatW tt6 = simde_mm256_shuffle_ps(t5, t7, SIMDE_MM_SHUFFLE(1, 0, 1, 0));
+	b2FloatW tt7 = simde_mm256_shuffle_ps(t5, t7, SIMDE_MM_SHUFFLE(3, 2, 3, 2));
 
 	b2SimdBody simdBody;
 	simdBody.v.X = simde_mm256_permute2f128_ps(tt0, tt4, 0x20);
@@ -470,14 +470,14 @@ static void b2ScatterBodies(b2SolverBody* restrict bodies, int32_t* restrict ind
 	b2FloatW t5 = simde_mm256_unpackhi_ps(simdBody->dp.Y, simdBody->da);
 	b2FloatW t6 = simde_mm256_unpacklo_ps(simdBody->invM, simdBody->invI);
 	b2FloatW t7 = simde_mm256_unpackhi_ps(simdBody->invM, simdBody->invI);
-	b2FloatW tt0 = simde_mm256_shuffle_ps(t0, t2, _MM_SHUFFLE(1, 0, 1, 0));
-	b2FloatW tt1 = simde_mm256_shuffle_ps(t0, t2, _MM_SHUFFLE(3, 2, 3, 2));
-	b2FloatW tt2 = simde_mm256_shuffle_ps(t1, t3, _MM_SHUFFLE(1, 0, 1, 0));
-	b2FloatW tt3 = simde_mm256_shuffle_ps(t1, t3, _MM_SHUFFLE(3, 2, 3, 2));
-	b2FloatW tt4 = simde_mm256_shuffle_ps(t4, t6, _MM_SHUFFLE(1, 0, 1, 0));
-	b2FloatW tt5 = simde_mm256_shuffle_ps(t4, t6, _MM_SHUFFLE(3, 2, 3, 2));
-	b2FloatW tt6 = simde_mm256_shuffle_ps(t5, t7, _MM_SHUFFLE(1, 0, 1, 0));
-	b2FloatW tt7 = simde_mm256_shuffle_ps(t5, t7, _MM_SHUFFLE(3, 2, 3, 2));
+	b2FloatW tt0 = simde_mm256_shuffle_ps(t0, t2, SIMDE_MM_SHUFFLE(1, 0, 1, 0));
+	b2FloatW tt1 = simde_mm256_shuffle_ps(t0, t2, SIMDE_MM_SHUFFLE(3, 2, 3, 2));
+	b2FloatW tt2 = simde_mm256_shuffle_ps(t1, t3, SIMDE_MM_SHUFFLE(1, 0, 1, 0));
+	b2FloatW tt3 = simde_mm256_shuffle_ps(t1, t3, SIMDE_MM_SHUFFLE(3, 2, 3, 2));
+	b2FloatW tt4 = simde_mm256_shuffle_ps(t4, t6, SIMDE_MM_SHUFFLE(1, 0, 1, 0));
+	b2FloatW tt5 = simde_mm256_shuffle_ps(t4, t6, SIMDE_MM_SHUFFLE(3, 2, 3, 2));
+	b2FloatW tt6 = simde_mm256_shuffle_ps(t5, t7, SIMDE_MM_SHUFFLE(1, 0, 1, 0));
+	b2FloatW tt7 = simde_mm256_shuffle_ps(t5, t7, SIMDE_MM_SHUFFLE(3, 2, 3, 2));
 
 	// I don't use any dummy body in the body array because this will lead to multithreaded sharing and the
 	// associated cache flushing.
@@ -771,7 +771,7 @@ void b2SolveContactsSIMD(int32_t startIndex, int32_t endIndex, b2SolverTaskConte
 
 			b2FloatW s = add(c->separation1, ds);
 
-			b2FloatW test = simde_mm256_cmp_ps(s, simde_mm256_setzero_ps(), _CMP_GT_OQ);
+			b2FloatW test = simde_mm256_cmp_ps(s, simde_mm256_setzero_ps(), SIMDE_CMP_GT_OQ);
 			b2FloatW specBias = mul(s, invDtMul);
 			b2FloatW softBias = simde_mm256_max_ps(mul(biasCoeff, s), minBiasVel);
 			b2FloatW bias = simde_mm256_blendv_ps(softBias, specBias, test);
@@ -811,7 +811,7 @@ void b2SolveContactsSIMD(int32_t startIndex, int32_t endIndex, b2SolverTaskConte
 
 			b2FloatW s = add(c->separation2, ds);
 
-			b2FloatW test = simde_mm256_cmp_ps(s, simde_mm256_setzero_ps(), _CMP_GT_OQ);
+			b2FloatW test = simde_mm256_cmp_ps(s, simde_mm256_setzero_ps(), SIMDE_CMP_GT_OQ);
 			b2FloatW specBias = mul(s, invDtMul);
 			b2FloatW softBias = simde_mm256_max_ps(mul(biasCoeff, s), minBiasVel);
 			b2FloatW bias = simde_mm256_blendv_ps(softBias, specBias, test);
@@ -932,8 +932,8 @@ void b2ApplyRestitutionSIMD(int32_t startIndex, int32_t endIndex, b2SolverTaskCo
 		// first point non-penetration constraint
 		{
 			// Set effective mass to zero if restitution should not be applied
-			b2FloatW test1 = simde_mm256_cmp_ps(add(c->relativeVelocity1, threshold), zero, _CMP_GT_OQ);
-			b2FloatW test2 = simde_mm256_cmp_ps(c->normalImpulse1, zero, _CMP_EQ_OQ);
+			b2FloatW test1 = simde_mm256_cmp_ps(add(c->relativeVelocity1, threshold), zero, SIMDE_CMP_GT_OQ);
+			b2FloatW test2 = simde_mm256_cmp_ps(c->normalImpulse1, zero, SIMDE_CMP_EQ_OQ);
 			b2FloatW test = simde_mm256_or_ps(test1, test2);
 			b2FloatW mass = simde_mm256_blendv_ps(c->normalMass1, zero, test);
 
@@ -966,8 +966,8 @@ void b2ApplyRestitutionSIMD(int32_t startIndex, int32_t endIndex, b2SolverTaskCo
 		// second point non-penetration constraint
 		{
 			// Set effective mass to zero if restitution should not be applied
-			b2FloatW test1 = simde_mm256_cmp_ps(add(c->relativeVelocity2, threshold), zero, _CMP_GT_OQ);
-			b2FloatW test2 = simde_mm256_cmp_ps(c->normalImpulse2, zero, _CMP_EQ_OQ);
+			b2FloatW test1 = simde_mm256_cmp_ps(add(c->relativeVelocity2, threshold), zero, SIMDE_CMP_GT_OQ);
+			b2FloatW test2 = simde_mm256_cmp_ps(c->normalImpulse2, zero, SIMDE_CMP_EQ_OQ);
 			b2FloatW test = simde_mm256_or_ps(test1, test2);
 			b2FloatW mass = simde_mm256_blendv_ps(c->normalMass2, zero, test);
 
diff --git a/src/graph.c b/src/graph.c
index 6a2e71f7..453b2d80 100644
--- a/src/graph.c
+++ b/src/graph.c
@@ -17,6 +17,8 @@
 
 #include "box2d/aabb.h"
 
+#include "x86/sse2.h"
+
 #include <limits.h>
 #include <stdatomic.h>
 #include <stdbool.h>
@@ -918,7 +920,7 @@ static void b2ExecuteMainStage(b2SolverStage* stage, b2SolverTaskContext* contex
 
 		while (atomic_load(&stage->completionCount) != blockCount)
 		{
-			_mm_pause();
+			simde_mm_pause();
 		}
 
 		atomic_store(&stage->completionCount, 0);
@@ -1081,7 +1083,7 @@ void b2SolverTask(int32_t startIndex, int32_t endIndex, uint32_t threadIndexDont
 		uint32_t syncBits = atomic_load(&context->syncBits);
 		while (syncBits == lastSyncBits)
 		{
-			_mm_pause();
+			simde_mm_pause();
 			syncBits = atomic_load(&context->syncBits);
 		}
 
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 16eefa87..15f0b765 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -15,12 +15,6 @@ set(BOX2D_TESTS
 
 add_executable(test ${BOX2D_TESTS})
 
-if ("${CMAKE_SYSTEM_NAME}" STREQUAL "Windows")
-	target_compile_options(test PRIVATE /W4 /WX /std:c17)
-else()
-	target_compile_options(test PRIVATE -Wall -Wextra -Wpedantic -Werror)
-endif()
-
 # Special access to Box2D internals for testing
 target_include_directories(test PRIVATE ${CMAKE_SOURCE_DIR}/src)
 
diff --git a/test/main.c b/test/main.c
index a59c83cb..67f7e03e 100644
--- a/test/main.c
+++ b/test/main.c
@@ -18,15 +18,15 @@
 //}
 #endif
 
-extern int BitSetTest();
-extern int MathTest();
-extern int CollisionTest();
-extern int DeterminismTest();
-extern int DistanceTest();
-extern int HelloWorld();
-extern int EmptyWorld();
-extern int ShapeTest();
-extern int TableTest();
+extern int BitSetTest(void);
+extern int MathTest(void);
+extern int CollisionTest(void);
+extern int DeterminismTest(void);
+extern int DistanceTest(void);
+extern int HelloWorld(void);
+extern int EmptyWorld(void);
+extern int ShapeTest(void);
+extern int TableTest(void);
 
 int main(void)
 {
diff --git a/test/test_bitset.c b/test/test_bitset.c
index fdec9a0a..4ba8e238 100644
--- a/test/test_bitset.c
+++ b/test/test_bitset.c
@@ -7,7 +7,7 @@
 
 #define COUNT 169
 
-int BitSetTest()
+int BitSetTest(void)
 {
 	b2BitSet bitSet = b2CreateBitSet(COUNT);
 	
diff --git a/test/test_collision.c b/test/test_collision.c
index 2f6e8593..62f7b7ce 100644
--- a/test/test_collision.c
+++ b/test/test_collision.c
@@ -5,7 +5,7 @@
 #include "box2d/math.h"
 #include "test_macros.h"
 
-static int AABBTest()
+static int AABBTest(void)
 {
 	b2AABB a;
 	a.lowerBound = (b2Vec2){-1.0f, -1.0f};
@@ -30,7 +30,7 @@ static int AABBTest()
 	return 0;
 }
 
-int CollisionTest()
+int CollisionTest(void)
 {
 	RUN_SUBTEST(AABBTest);
 
diff --git a/test/test_determinism.c b/test/test_determinism.c
index 6dac0910..751dfbe1 100644
--- a/test/test_determinism.c
+++ b/test/test_determinism.c
@@ -188,7 +188,7 @@ void TiltedStacks(int testIndex, int workerCount)
 }
 
 // Test multi-threaded determinism.
-int DeterminismTest()
+int DeterminismTest(void)
 {
 	// Test 1 : 4 threads
 	TiltedStacks(0, 16);
diff --git a/test/test_distance.c b/test/test_distance.c
index 5bcfd899..955bc7bd 100644
--- a/test/test_distance.c
+++ b/test/test_distance.c
@@ -8,7 +8,7 @@
 
 #include <float.h>
 
-static int SegmentDistanceTest()
+static int SegmentDistanceTest(void)
 {
 	b2Vec2 p1 = {-1.0f, -1.0f};
 	b2Vec2 q1 = {-1.0f, 1.0f};
@@ -28,7 +28,7 @@ static int SegmentDistanceTest()
 	return 0;
 }
 
-static int ShapeDistanceTest()
+static int ShapeDistanceTest(void)
 {
 	b2Vec2 vas[] = {
 		(b2Vec2){-1.0f, -1.0f},
@@ -56,7 +56,7 @@ static int ShapeDistanceTest()
 	return 0;
 }
 
-static int ShapeCastTest()
+static int ShapeCastTest(void)
 {
 	b2Vec2 vas[] = {
 		(b2Vec2){-1.0f, -1.0f},
@@ -85,7 +85,7 @@ static int ShapeCastTest()
 	return 0;
 }
 
-static int TimeOfImpactTest()
+static int TimeOfImpactTest(void)
 {
 	b2Vec2 vas[] = {
 		(b2Vec2){-1.0f, -1.0f},
@@ -113,7 +113,7 @@ static int TimeOfImpactTest()
 	return 0;
 }
 
-int DistanceTest()
+int DistanceTest(void)
 {
 	RUN_SUBTEST(SegmentDistanceTest);
 	RUN_SUBTEST(ShapeDistanceTest);
diff --git a/test/test_math.c b/test/test_math.c
index fabe10ae..306801a5 100644
--- a/test/test_math.c
+++ b/test/test_math.c
@@ -6,7 +6,7 @@
 
 #include <float.h>
 
-int MathTest()
+int MathTest(void)
 {
 	b2Vec2 zero = b2Vec2_zero;
 	b2Vec2 one = {1.0f, 1.0f};
@@ -30,14 +30,14 @@ int MathTest()
 
 	b2Vec2 u = b2TransformPoint(xf, two);
 
-	ENSURE_SMALL(u.x - v.x, FLT_EPSILON);
-	ENSURE_SMALL(u.y - v.y, FLT_EPSILON);
+	ENSURE_SMALL(u.x - v.x, 10.0f * FLT_EPSILON);
+	ENSURE_SMALL(u.y - v.y, 10.0f * FLT_EPSILON);
 
 	v = b2TransformPoint(xf1, two);
 	v = b2InvTransformPoint(xf1, v);
 
-	ENSURE_SMALL(v.x - two.x, 2.0f * FLT_EPSILON);
-	ENSURE_SMALL(v.y - two.y, 2.0f * FLT_EPSILON);
+	ENSURE_SMALL(v.x - two.x, 8.0f * FLT_EPSILON);
+	ENSURE_SMALL(v.y - two.y, 8.0f * FLT_EPSILON);
 
 	return 0;
 }
diff --git a/test/test_shape.c b/test/test_shape.c
index 59d2543d..24d3cc53 100644
--- a/test/test_shape.c
+++ b/test/test_shape.c
@@ -15,7 +15,7 @@ static b2Segment segment = {{0.0f, 1.0f}, {0.0f, -1.0f}};
 
 #define N 4
 
-static int ShapeMassTest()
+static int ShapeMassTest(void)
 {
 	{
 		b2MassData md = b2ComputeCircleMass(&circle, 1.0f);
@@ -72,7 +72,7 @@ static int ShapeMassTest()
 	return 0;
 }
 
-static int ShapeAABBTest()
+static int ShapeAABBTest(void)
 {
 	{
 		b2AABB b = b2ComputeCircleAABB(&circle, b2Transform_identity);
@@ -101,7 +101,7 @@ static int ShapeAABBTest()
 	return 0;
 }
 
-static int PointInShapeTest()
+static int PointInShapeTest(void)
 {
 	b2Vec2 p1 = {0.5f, 0.5f};
 	b2Vec2 p2 = {4.0f, -4.0f};
@@ -125,7 +125,7 @@ static int PointInShapeTest()
 	return 0;
 }
 
-static int RayCastShapeTest()
+static int RayCastShapeTest(void)
 {
 	b2RayCastInput input = {{-4.0f, 0.0f}, {8.0f, 0.0f}, 1.0f};
 	
@@ -156,7 +156,7 @@ static int RayCastShapeTest()
 	return 0;
 }
 
-int ShapeTest()
+int ShapeTest(void)
 {
 	box = b2MakeBox(1.0f, 1.0f);
 
diff --git a/test/test_table.c b/test/test_table.c
index eb8541f7..80e20bc2 100644
--- a/test/test_table.c
+++ b/test/test_table.c
@@ -9,7 +9,7 @@
 #define ITEM_COUNT ((SET_SPAN * SET_SPAN - SET_SPAN) / 2)
 
 
-int TableTest()
+int TableTest(void)
 {
 	const int32_t N = SET_SPAN;
 	const uint32_t itemCount = ITEM_COUNT;
diff --git a/test/test_world.c b/test/test_world.c
index 228e2e5c..463ccd86 100644
--- a/test/test_world.c
+++ b/test/test_world.c
@@ -13,7 +13,7 @@
 // box.
 // There are no graphics for this example. Box2D is meant to be used
 // with your rendering engine in your game engine.
-int HelloWorld()
+int HelloWorld(void)
 {
 	// Define the gravity vector.
 	b2Vec2 gravity = {0.0f, -10.0f};
@@ -96,7 +96,7 @@ int HelloWorld()
 	return 0;
 }
 
-int EmptyWorld()
+int EmptyWorld(void)
 {
 	b2WorldDef worldDef = b2DefaultWorldDef();
 	b2WorldId worldId = b2CreateWorld(&worldDef);