diff --git a/tests/lapi/lib.lua b/tests/lapi/lib.lua
index a1e6cfee..09933d44 100644
--- a/tests/lapi/lib.lua
+++ b/tests/lapi/lib.lua
@@ -7,12 +7,31 @@ Test helpers.
 
 -- The function determines a Lua version.
 local function lua_version()
+    local major, minor = _VERSION:match("([%d]+)%.(%d+)")
+    local version = {
+        major = tonumber(major),
+        minor = tonumber(minor),
+    }
     local is_luajit, _ = pcall(require, "jit")
-    if is_luajit then
-        return "LuaJIT"
+    local lua_name = is_luajit and "LuaJIT" or "PUC Rio Lua"
+    return lua_name, version
+end
+
+local function version_ge(version1, version2)
+    if version1.major ~= version2.major then
+        return version1.major > version2.major
+    else
+        return version1.minor >= version2.minor
     end
+end
 
-    return _VERSION
+local function lua_current_version_ge_than(major, minor)
+    local _, current_version = lua_version()
+    return version_ge(current_version, { major = major, minor = minor })
+end
+
+local function lua_current_version_lt_than(major, minor)
+    return not lua_current_version_ge_than(major, minor)
 end
 
 -- By default `lua_Integer` is ptrdiff_t in Lua 5.1 and Lua 5.2
@@ -56,9 +75,22 @@ local function bitwise_op(op_name)
     end
 end
 
+local function math_pow(x, y)
+    return x ^ y
+end
+
+local function approx_equal(a, b, epsilon)
+    local abs = math.abs
+    return abs(a - b) <= ((abs(a) < abs(b) and abs(b) or abs(a)) * epsilon)
+end
+
 return {
-    lua_version = lua_version,
+    approx_equal = approx_equal,
     bitwise_op = bitwise_op,
+    lua_version = lua_version,
+    lua_current_version_ge_than = lua_current_version_ge_than,
+    lua_current_version_lt_than = lua_current_version_lt_than,
+    math_pow = math_pow,
     MAX_INT64 = MAX_INT64,
     MIN_INT64 = MIN_INT64,
     MAX_INT = MAX_INT,
diff --git a/tests/lapi/math_abs_test.lua b/tests/lapi/math_abs_test.lua
new file mode 100644
index 00000000..62679608
--- /dev/null
+++ b/tests/lapi/math_abs_test.lua
@@ -0,0 +1,33 @@
+--[[
+SPDX-License-Identifier: ISC
+Copyright (c) 2023-2025, Sergey Bronnikov.
+
+18 – The Mathematical Library
+https://www.lua.org/pil/18.html
+
+6.7 – Mathematical Functions
+https://www.lua.org/manual/5.3/manual.html#6.7
+
+Misleading assertion in asm_fload() for mips,
+https://github.com/LuaJIT/LuaJIT/issues/1043
+
+Synopsis: math.abs(x)
+]]
+
+local luzer = require("luzer")
+local test_lib = require("lib")
+
+local function TestOneInput(buf)
+    local fdp = luzer.FuzzedDataProvider(buf)
+    local n = fdp:consume_number(test_lib.MIN_INT, test_lib.MAX_INT)
+    local abs = n
+    if abs < 0 then
+        abs = -abs
+    end
+    assert(math.abs(n) == abs)
+end
+
+local args = {
+    artifact_prefix = "math_abs_",
+}
+luzer.Fuzz(TestOneInput, nil, args)
diff --git a/tests/lapi/math_acos_test.lua b/tests/lapi/math_acos_test.lua
new file mode 100644
index 00000000..5e595dd2
--- /dev/null
+++ b/tests/lapi/math_acos_test.lua
@@ -0,0 +1,33 @@
+--[[
+SPDX-License-Identifier: ISC
+Copyright (c) 2023-2025, Sergey Bronnikov.
+
+18 – The Mathematical Library
+https://www.lua.org/pil/18.html
+
+6.7 – Mathematical Functions
+https://www.lua.org/manual/5.3/manual.html#6.7
+
+Synopsis: math.acos(x)
+]]
+
+local luzer = require("luzer")
+local test_lib = require("lib")
+
+local function TestOneInput(buf)
+    local fdp = luzer.FuzzedDataProvider(buf)
+    local x = fdp:consume_number(-1, 1)
+    local y = math.acos(x)
+    assert(y >= 0)
+    assert(y <= math.pi)
+    local epsilon = 1^-10
+    if x ~= 0 then
+        assert(test_lib.approx_equal(y, math.pi - math.acos(-x), epsilon))
+        assert(test_lib.approx_equal(math.cos(y), x, epsilon))
+    end
+end
+
+local args = {
+    artifact_prefix = "math_acos_",
+}
+luzer.Fuzz(TestOneInput, nil, args)
diff --git a/tests/lapi/math_asin_test.lua b/tests/lapi/math_asin_test.lua
new file mode 100644
index 00000000..5e15cb16
--- /dev/null
+++ b/tests/lapi/math_asin_test.lua
@@ -0,0 +1,31 @@
+--[[
+SPDX-License-Identifier: ISC
+Copyright (c) 2023-2025, Sergey Bronnikov.
+
+18 – The Mathematical Library
+https://www.lua.org/pil/18.html
+
+6.7 – Mathematical Functions
+https://www.lua.org/manual/5.3/manual.html#6.7
+
+Synopsis: math.asin(x)
+]]
+
+local luzer = require("luzer")
+local test_lib = require("lib")
+
+local function TestOneInput(buf)
+    local fdp = luzer.FuzzedDataProvider(buf)
+    local x = fdp:consume_number(-1, 1)
+    local y = math.asin(x)
+    assert(type(y) == "number")
+    assert(y >= -math.pi / 2)
+    assert(y <=  math.pi / 2)
+    local epsilon = 1^-10
+    assert(test_lib.approx_equal(math.sin(y), x, epsilon))
+end
+
+local args = {
+    artifact_prefix = "math_asin_",
+}
+luzer.Fuzz(TestOneInput, nil, args)
diff --git a/tests/lapi/math_atan_test.lua b/tests/lapi/math_atan_test.lua
new file mode 100644
index 00000000..b947d4e5
--- /dev/null
+++ b/tests/lapi/math_atan_test.lua
@@ -0,0 +1,30 @@
+--[[
+SPDX-License-Identifier: ISC
+Copyright (c) 2023-2025, Sergey Bronnikov.
+
+18 – The Mathematical Library
+https://www.lua.org/pil/18.html
+
+6.7 – Mathematical Functions
+https://www.lua.org/manual/5.3/manual.html#6.7
+
+Synopsis: math.atan(y [, x])
+]]
+
+local luzer = require("luzer")
+local test_lib = require("lib")
+
+local function TestOneInput(buf)
+    local fdp = luzer.FuzzedDataProvider(buf)
+    local x = fdp:consume_number(test_lib.MIN_INT, test_lib.MAX_INT)
+    local y = math.atan(x)
+    assert(type(y) == "number")
+    assert(y >= -math.pi / 2)
+    assert(y <=  math.pi / 2)
+    assert(math.atan(-x) == -y)
+end
+
+local args = {
+    artifact_prefix = "math_atan_",
+}
+luzer.Fuzz(TestOneInput, nil, args)
diff --git a/tests/lapi/math_ceil_test.lua b/tests/lapi/math_ceil_test.lua
new file mode 100644
index 00000000..599bff3f
--- /dev/null
+++ b/tests/lapi/math_ceil_test.lua
@@ -0,0 +1,39 @@
+--[[
+SPDX-License-Identifier: ISC
+Copyright (c) 2023-2025, Sergey Bronnikov.
+
+18 – The Mathematical Library
+https://www.lua.org/pil/18.html
+
+6.7 – Mathematical Functions
+https://www.lua.org/manual/5.3/manual.html#6.7
+
+vm_mips.dasc assumes 32-bit FPU register model,
+https://github.com/LuaJIT/LuaJIT/issues/1040
+
+math.ceil fails to return -0 for -1 < x < -0.5,
+https://github.com/LuaJIT/LuaJIT/issues/859
+
+ARM64 - corrupted local variable on trace exit / snapshot replay,
+https://github.com/LuaJIT/LuaJIT/issues/579
+
+x86/x64: Fix math.ceil(-0.9) result sign,
+https://github.com/LuaJIT/LuaJIT/issues/859
+
+Synopsis: math.ceil(x)
+]]
+
+local luzer = require("luzer")
+local test_lib = require("lib")
+
+local function TestOneInput(buf)
+    local fdp = luzer.FuzzedDataProvider(buf)
+    local x = fdp:consume_number(test_lib.MIN_INT, test_lib.MAX_INT)
+    local res = math.ceil(x)
+    assert(type(res) == "number")
+end
+
+local args = {
+    artifact_prefix = "math_ceil_",
+}
+luzer.Fuzz(TestOneInput, nil, args)
diff --git a/tests/lapi/math_cos_test.lua b/tests/lapi/math_cos_test.lua
new file mode 100644
index 00000000..b77fedb5
--- /dev/null
+++ b/tests/lapi/math_cos_test.lua
@@ -0,0 +1,38 @@
+--[[
+SPDX-License-Identifier: ISC
+Copyright (c) 2023-2025, Sergey Bronnikov.
+
+18 – The Mathematical Library
+https://www.lua.org/pil/18.html
+
+6.7 – Mathematical Functions
+https://www.lua.org/manual/5.3/manual.html#6.7
+
+Synopsis: math.cos(x)
+]]
+
+local luzer = require("luzer")
+local test_lib = require("lib")
+
+local function TestOneInput(buf)
+    local fdp = luzer.FuzzedDataProvider(buf)
+    local x = fdp:consume_number(test_lib.MIN_INT, test_lib.MAX_INT)
+    local cos_x = math.cos(x)
+    assert(type(cos_x) == "number")
+    assert(cos_x >= -1 and cos_x <= 1)
+    local epsilon = 1^-10
+
+    local n = fdp:consume_number(0, 100)
+    -- Calculate the functions of the form `cos(i*pi - x), where
+    -- i = 1, 3, 5, etc. These functions are equivalent, given the
+    -- trigonometric identity.
+    for i = 1, n do
+        assert(test_lib.approx_equal(
+            math.abs(math.cos(i * math.pi - x)), math.abs(cos_x), epsilon))
+    end
+end
+
+local args = {
+    artifact_prefix = "math_cos_",
+}
+luzer.Fuzz(TestOneInput, nil, args)
diff --git a/tests/lapi/math_deg_test.lua b/tests/lapi/math_deg_test.lua
new file mode 100644
index 00000000..26f87938
--- /dev/null
+++ b/tests/lapi/math_deg_test.lua
@@ -0,0 +1,27 @@
+--[[
+SPDX-License-Identifier: ISC
+Copyright (c) 2023-2025, Sergey Bronnikov.
+
+18 – The Mathematical Library
+https://www.lua.org/pil/18.html
+
+6.7 – Mathematical Functions
+https://www.lua.org/manual/5.3/manual.html#6.7
+
+Synopsis: math.deg(x)
+]]
+
+local luzer = require("luzer")
+local test_lib = require("lib")
+
+local function TestOneInput(buf)
+    local fdp = luzer.FuzzedDataProvider(buf)
+    local a = fdp:consume_number(test_lib.MIN_INT, test_lib.MAX_INT)
+    local res = math.deg(a)
+    assert(type(res) == "number")
+end
+
+local args = {
+    artifact_prefix = "math_deg_",
+}
+luzer.Fuzz(TestOneInput, nil, args)
diff --git a/tests/lapi/math_exp_test.lua b/tests/lapi/math_exp_test.lua
new file mode 100644
index 00000000..a6b47f5b
--- /dev/null
+++ b/tests/lapi/math_exp_test.lua
@@ -0,0 +1,27 @@
+--[[
+SPDX-License-Identifier: ISC
+Copyright (c) 2023-2025, Sergey Bronnikov.
+
+18 – The Mathematical Library
+https://www.lua.org/pil/18.html
+
+6.7 – Mathematical Functions
+https://www.lua.org/manual/5.3/manual.html#6.7
+
+Synopsis: math.exp(x)
+]]
+
+local luzer = require("luzer")
+local test_lib = require("lib")
+
+local function TestOneInput(buf)
+    local fdp = luzer.FuzzedDataProvider(buf)
+    local a = fdp:consume_number(test_lib.MIN_INT, test_lib.MAX_INT)
+    local res = math.exp(a)
+    assert(type(res) == "number")
+end
+
+local args = {
+    artifact_prefix = "math_exp_",
+}
+luzer.Fuzz(TestOneInput, nil, args)
diff --git a/tests/lapi/math_floor_test.lua b/tests/lapi/math_floor_test.lua
new file mode 100644
index 00000000..ad6d034f
--- /dev/null
+++ b/tests/lapi/math_floor_test.lua
@@ -0,0 +1,27 @@
+--[[
+SPDX-License-Identifier: ISC
+Copyright (c) 2023-2025, Sergey Bronnikov.
+
+18 – The Mathematical Library
+https://www.lua.org/pil/18.html
+
+6.7 – Mathematical Functions
+https://www.lua.org/manual/5.3/manual.html#6.7
+
+Synopsis: math.floor(x)
+]]
+
+local luzer = require("luzer")
+local test_lib = require("lib")
+
+local function TestOneInput(buf)
+    local fdp = luzer.FuzzedDataProvider(buf)
+    local a = fdp:consume_number(test_lib.MIN_INT, test_lib.MAX_INT)
+    local res = math.floor(a)
+    assert(type(res) == "number")
+end
+
+local args = {
+    artifact_prefix = "math_floor_",
+}
+luzer.Fuzz(TestOneInput, nil, args)
diff --git a/tests/lapi/math_fmod_test.lua b/tests/lapi/math_fmod_test.lua
new file mode 100644
index 00000000..759b7812
--- /dev/null
+++ b/tests/lapi/math_fmod_test.lua
@@ -0,0 +1,28 @@
+--[[
+SPDX-License-Identifier: ISC
+Copyright (c) 2023-2025, Sergey Bronnikov.
+
+18 – The Mathematical Library
+https://www.lua.org/pil/18.html
+
+6.7 – Mathematical Functions
+https://www.lua.org/manual/5.3/manual.html#6.7
+
+Synopsis: math.fmod(x, y)
+]]
+
+local luzer = require("luzer")
+local test_lib = require("lib")
+
+local function TestOneInput(buf)
+    local fdp = luzer.FuzzedDataProvider(buf)
+    local x = fdp:consume_number(test_lib.MIN_INT, test_lib.MAX_INT)
+    local y = fdp:consume_number(test_lib.MIN_INT, test_lib.MAX_INT)
+    local res = math.fmod(x, y)
+    assert(type(res) == "number")
+end
+
+local args = {
+    artifact_prefix = "math_fmod_",
+}
+luzer.Fuzz(TestOneInput, nil, args)
diff --git a/tests/lapi/math_log_test.lua b/tests/lapi/math_log_test.lua
new file mode 100644
index 00000000..30722956
--- /dev/null
+++ b/tests/lapi/math_log_test.lua
@@ -0,0 +1,70 @@
+--[[
+SPDX-License-Identifier: ISC
+Copyright (c) 2023-2025, Sergey Bronnikov.
+
+18 – The Mathematical Library
+https://www.lua.org/pil/18.html
+
+6.7 – Mathematical Functions
+https://www.lua.org/manual/5.3/manual.html#6.7
+
+Two-parameter logarithm gives incorrect answers for matching inputs,
+https://github.com/LuaJIT/LuaJIT/issues/1240
+
+Synopsis: math.log(x [, b])
+]]
+
+local luzer = require("luzer")
+local test_lib = require("lib")
+
+-- The function `math.pow()` has been deprecated in PUC Rio Lua
+-- 5.3, see Lua 5.3 Reference Manual, 8.2 – Changes in the
+-- Libraries.
+--
+-- 1. https://www.lua.org/manual/5.3/manual.html
+local pow
+if test_lib.lua_current_version_ge_than(5, 3) then
+    pow = test_lib.math_pow
+else
+    pow = math.pow
+end
+
+local function TestOneInput(buf, _size)
+    local fdp = luzer.FuzzedDataProvider(buf)
+    -- The natural logarithm (base e) of x. If x is ±0,
+    -- returns -Infinity. If x < 0, returns NaN.
+    local x = fdp:consume_number(0, test_lib.MAX_INT)
+    local y = fdp:consume_number(0, test_lib.MAX_INT)
+    local b = fdp:consume_number(test_lib.MIN_INT, test_lib.MAX_INT)
+    if b < 0 or b == 1 then return -1 end
+
+    local eps = 1^-10
+
+    -- Product rule.
+    assert(test_lib.approx_equal(
+        math.log(x * y, b), math.log(x, b) + math.log(y, b), eps))
+    -- Quotient rule.
+    assert(test_lib.approx_equal(
+        math.log(x / y, b), math.log(x, b) - math.log(y, b), eps))
+    -- Power rule.
+    assert(test_lib.approx_equal(
+        math.log(pow(x, y), b), y * math.log(x, b), eps))
+    -- Inverse property of logarithm.
+    assert(test_lib.approx_equal(math.log(pow(b, x), b), x, eps))
+    -- Inverse property of exponent.
+    assert(test_lib.approx_equal(pow(b, math.log(x, b)), x, eps))
+    -- Zero rule.
+    assert(math.log(1, b) == 0)
+    -- Identity rule.
+    assert(test_lib.approx_equal(math.log(b, b), 1, eps))
+    -- Change of base formula.
+    local log_b_y = math.log(b, y)
+    if log_b_y ~= 0 then
+        assert(test_lib.approx_equal(math.log(x, b), math.log(x, y) / log_b_y, eps))
+    end
+end
+
+local args = {
+    artifact_prefix = "math_log_",
+}
+luzer.Fuzz(TestOneInput, nil, args)
diff --git a/tests/lapi/math_modf_test.lua b/tests/lapi/math_modf_test.lua
new file mode 100644
index 00000000..8a18d50b
--- /dev/null
+++ b/tests/lapi/math_modf_test.lua
@@ -0,0 +1,30 @@
+--[[
+SPDX-License-Identifier: ISC
+Copyright (c) 2023-2025, Sergey Bronnikov.
+
+18 – The Mathematical Library
+https://www.lua.org/pil/18.html
+
+6.7 – Mathematical Functions
+https://www.lua.org/manual/5.3/manual.html#6.7
+
+Don't compile math.modf() anymore,
+https://github.com/LuaJIT/LuaJIT/commit/d75e2627
+
+Synopsis: math.modf(x)
+]]
+
+local luzer = require("luzer")
+local test_lib = require("lib")
+
+local function TestOneInput(buf)
+    local fdp = luzer.FuzzedDataProvider(buf)
+    local x = fdp:consume_number(test_lib.MIN_INT, test_lib.MAX_INT)
+    local res = math.modf(x)
+    assert(type(res) == "number")
+end
+
+local args = {
+    artifact_prefix = "math_modf_",
+}
+luzer.Fuzz(TestOneInput, nil, args)
diff --git a/tests/lapi/math_pow_test.lua b/tests/lapi/math_pow_test.lua
new file mode 100644
index 00000000..aa376292
--- /dev/null
+++ b/tests/lapi/math_pow_test.lua
@@ -0,0 +1,48 @@
+--[[
+SPDX-License-Identifier: ISC
+Copyright (c) 2023-2025, Sergey Bronnikov.
+
+18 – The Mathematical Library
+https://www.lua.org/pil/18.html
+
+6.7 – Mathematical Functions
+https://www.lua.org/manual/5.3/manual.html#6.7
+
+Revert to trival pow() optimizations to prevent inaccuracies,
+https://github.com/LuaJIT/LuaJIT/commit/96d6d503
+
+Optimizations for power operator a^b,
+https://github.com/LuaJIT/LuaJIT/issues/9
+
+Fix pow() optimization inconsistencies,
+https://github.com/LuaJIT/LuaJIT/commit/9512d5c1
+
+Synopsis: math.pow(x, y)
+]]
+
+local luzer = require("luzer")
+local test_lib = require("lib")
+
+-- The function `math.pow()` has been deprecated in PUC Rio Lua 5.3,
+-- see Lua 5.3 Reference Manual, 8.2 – Changes in the Libraries.
+--
+-- 1. https://www.lua.org/manual/5.3/manual.html
+local pow
+if test_lib.lua_current_version_ge_than(5, 3) then
+    pow = test_lib.math_pow
+else
+    pow = math.pow
+end
+
+local function TestOneInput(buf, _size)
+    local fdp = luzer.FuzzedDataProvider(buf)
+    local x = fdp:consume_number(test_lib.MIN_INT, test_lib.MAX_INT)
+    local y = fdp:consume_number(test_lib.MIN_INT, test_lib.MAX_INT)
+    local res = pow(x, y)
+    assert(type(res) == "number")
+end
+
+local args = {
+    artifact_prefix = "math_pow_",
+}
+luzer.Fuzz(TestOneInput, nil, args)
diff --git a/tests/lapi/math_rad_test.lua b/tests/lapi/math_rad_test.lua
new file mode 100644
index 00000000..ea871f9a
--- /dev/null
+++ b/tests/lapi/math_rad_test.lua
@@ -0,0 +1,27 @@
+--[[
+SPDX-License-Identifier: ISC
+Copyright (c) 2023-2025, Sergey Bronnikov.
+
+18 – The Mathematical Library
+https://www.lua.org/pil/18.html
+
+6.7 – Mathematical Functions
+https://www.lua.org/manual/5.3/manual.html#6.7
+
+Synopsis: math.rad(x)
+]]
+
+local luzer = require("luzer")
+local test_lib = require("lib")
+
+local function TestOneInput(buf, _size)
+    local fdp = luzer.FuzzedDataProvider(buf)
+    local x = fdp:consume_number(test_lib.MIN_INT, test_lib.MAX_INT)
+    local res = math.rad(x)
+    assert(type(res) == "number")
+end
+
+local args = {
+    artifact_prefix = "math_rad_",
+}
+luzer.Fuzz(TestOneInput, nil, args)
diff --git a/tests/lapi/math_randomseed_test.lua b/tests/lapi/math_randomseed_test.lua
new file mode 100644
index 00000000..1703c200
--- /dev/null
+++ b/tests/lapi/math_randomseed_test.lua
@@ -0,0 +1,33 @@
+--[=====[
+SPDX-License-Identifier: ISC
+Copyright (c) 2023-2025, Sergey Bronnikov.
+
+18 – The Mathematical Library
+https://www.lua.org/pil/18.html
+
+6.7 – Mathematical Functions
+https://www.lua.org/manual/5.3/manual.html#6.7
+
+Synopsis: math.randomseed([x [, y]])
+--]=====]
+
+local luzer = require("luzer")
+local test_lib = require("lib")
+
+local function TestOneInput(buf)
+    local fdp = luzer.FuzzedDataProvider(buf)
+    local x = fdp:consume_integer(test_lib.MIN_INT, test_lib.MAX_INT)
+    local y = fdp:consume_integer(test_lib.MIN_INT, test_lib.MAX_INT)
+    -- Since Lua 5.4 the function returns the two seed components
+    -- that were effectively used, so that setting them again
+    -- repeats the sequence.
+    local a, b = math.randomseed(x, y)
+    if test_lib.lua_current_version_ge_than(5, 4) then
+        assert(type(a) == "number" and type(b) == "number")
+    end
+end
+
+local args = {
+    artifact_prefix = "math_randomseed_",
+}
+luzer.Fuzz(TestOneInput, nil, args)
diff --git a/tests/lapi/math_sin_test.lua b/tests/lapi/math_sin_test.lua
new file mode 100644
index 00000000..34fed20c
--- /dev/null
+++ b/tests/lapi/math_sin_test.lua
@@ -0,0 +1,40 @@
+--[[
+SPDX-License-Identifier: ISC
+Copyright (c) 2023-2025, Sergey Bronnikov.
+
+18 – The Mathematical Library
+https://www.lua.org/pil/18.html
+
+6.7 – Mathematical Functions
+https://www.lua.org/manual/5.3/manual.html#6.7
+
+Synopsis: math.sin(x)
+]]
+
+local luzer = require("luzer")
+local test_lib = require("lib")
+
+local function TestOneInput(buf)
+    local fdp = luzer.FuzzedDataProvider(buf)
+    local x = fdp:consume_number(test_lib.MIN_INT, test_lib.MAX_INT)
+    local sin_x = math.sin(x)
+    assert(type(sin_x) == "number")
+    assert(sin_x >= -1 and sin_x <= 1)
+    local cos_x = math.cos(x)
+    local epsilon = 1^-10
+    assert(test_lib.approx_equal(cos_x^2 + sin_x^2, 1, epsilon))
+
+    local n = fdp:consume_number(0, 100)
+    -- Calculate the functions of the form `sin(i*pi - x), where
+    -- i = 1, 3, 5, etc. These functions are equivalent, given the
+    -- trigonometric identity.
+    for i = 1, n do
+        assert(test_lib.approx_equal(
+            math.abs(math.sin(i * math.pi - x)), math.abs(sin_x), epsilon))
+    end
+end
+
+local args = {
+    artifact_prefix = "math_sin_",
+}
+luzer.Fuzz(TestOneInput, nil, args)
diff --git a/tests/lapi/math_sqrt_test.lua b/tests/lapi/math_sqrt_test.lua
new file mode 100644
index 00000000..79ead101
--- /dev/null
+++ b/tests/lapi/math_sqrt_test.lua
@@ -0,0 +1,41 @@
+--[[
+SPDX-License-Identifier: ISC
+Copyright (c) 2023-2025, Sergey Bronnikov.
+
+18 – The Mathematical Library
+https://www.lua.org/pil/18.html
+
+6.7 – Mathematical Functions
+https://www.lua.org/manual/5.3/manual.html#6.7
+
+Sqrt(x) and x^0.5 not interchangeable,
+https://github.com/LuaJIT/LuaJIT/issues/684
+
+Synopsis: math.sqrt(x)
+
+See properties in
+"ESA/390 Enhanced Floating Point Support: An Overview"
+(The Facts of Floating Point Arithmetic) [1].
+
+1. http://ftpmirror.your.org/pub/misc/ftp.software.ibm.com/software/websphere/awdtools/hlasm/sh93fpov.pdf
+]]
+
+local luzer = require("luzer")
+local test_lib = require("lib")
+
+local function TestOneInput(buf)
+    local fdp = luzer.FuzzedDataProvider(buf)
+    local x = fdp:consume_number(0, test_lib.MAX_INT)
+    assert(type(x) == "number")
+    -- Note, `math.sqrt(x)` and `x^0.5` are not interchangeable,
+    -- see [1].
+    --
+    -- 1. https://github.com/LuaJIT/LuaJIT/issues/684#issuecomment-822427297
+    local epsilon = 1^-10
+    assert(test_lib.approx_equal(math.sqrt(x), x^0.5, epsilon))
+end
+
+local args = {
+    artifact_prefix = "math_sqrt_",
+}
+luzer.Fuzz(TestOneInput, nil, args)
diff --git a/tests/lapi/math_tan_test.lua b/tests/lapi/math_tan_test.lua
new file mode 100644
index 00000000..08174f83
--- /dev/null
+++ b/tests/lapi/math_tan_test.lua
@@ -0,0 +1,33 @@
+--[[
+SPDX-License-Identifier: ISC
+Copyright (c) 2023-2025, Sergey Bronnikov.
+
+18 – The Mathematical Library
+https://www.lua.org/pil/18.html
+
+6.7 – Mathematical Functions
+https://www.lua.org/manual/5.3/manual.html#6.7
+
+Synopsis: math.tan(x)
+]]
+
+local luzer = require("luzer")
+local test_lib = require("lib")
+
+local function TestOneInput(buf)
+    local fdp = luzer.FuzzedDataProvider(buf)
+    local x = fdp:consume_number(test_lib.MIN_INT, test_lib.MAX_INT)
+    local sin_x = math.sin(x)
+    local cos_x = math.cos(x)
+    local tan_x = math.tan(x)
+
+    local epsilon = 1^-10
+    if cos_x ~= 0 then
+        assert(test_lib.approx_equal(tan_x, sin_x / cos_x, epsilon))
+    end
+end
+
+local args = {
+    artifact_prefix = "math_tan_",
+}
+luzer.Fuzz(TestOneInput, nil, args)
diff --git a/tests/lapi/math_tointeger_test.lua b/tests/lapi/math_tointeger_test.lua
new file mode 100644
index 00000000..d048f2eb
--- /dev/null
+++ b/tests/lapi/math_tointeger_test.lua
@@ -0,0 +1,36 @@
+--[[
+SPDX-License-Identifier: ISC
+Copyright (c) 2023-2025, Sergey Bronnikov.
+
+18 – The Mathematical Library
+https://www.lua.org/pil/18.html
+
+6.7 – Mathematical Functions
+https://www.lua.org/manual/5.3/manual.html#6.7
+
+Synopsis: math.tointeger(x)
+]]
+
+local luzer = require("luzer")
+local test_lib = require("lib")
+
+-- The function `math.tointeger()` is available since Lua 5.3.
+if test_lib.lua_current_version_lt_than(5, 3) then
+    print("Unsupported version.")
+    os.exit(0)
+end
+
+local function TestOneInput(buf)
+    local fdp = luzer.FuzzedDataProvider(buf)
+    local max_len = fdp:consume_integer(0, test_lib.MAX_INT)
+    local x = fdp:consume_string(max_len)
+    local res = math.tointeger(x)
+    assert(type(res) == "number" or
+           res == "fail" or
+           res == nil)
+end
+
+local args = {
+    artifact_prefix = "math_tointeger_",
+}
+luzer.Fuzz(TestOneInput, nil, args)
diff --git a/tests/lapi/math_ult_test.lua b/tests/lapi/math_ult_test.lua
new file mode 100644
index 00000000..00aa05e2
--- /dev/null
+++ b/tests/lapi/math_ult_test.lua
@@ -0,0 +1,34 @@
+--[[
+SPDX-License-Identifier: ISC
+Copyright (c) 2023-2025, Sergey Bronnikov.
+
+18 – The Mathematical Library
+https://www.lua.org/pil/18.html
+
+6.7 – Mathematical Functions
+https://www.lua.org/manual/5.3/manual.html#6.7
+
+Synopsis: math.ult(m, n)
+]]
+
+local luzer = require("luzer")
+local test_lib = require("lib")
+
+-- The function `math.ult()` is available since Lua 5.3.
+if test_lib.lua_current_version_lt_than(5, 3) then
+    print("Unsupported version.")
+    os.exit(0)
+end
+
+local function TestOneInput(buf)
+    local fdp = luzer.FuzzedDataProvider(buf)
+    local m = fdp:consume_integer(test_lib.MIN_INT, test_lib.MAX_INT)
+    local n = fdp:consume_integer(test_lib.MIN_INT, test_lib.MAX_INT)
+    local res = math.ult(m, n)
+    assert(type(res) == "boolean")
+end
+
+local args = {
+    artifact_prefix = "math_ult_",
+}
+luzer.Fuzz(TestOneInput, nil, args)