diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4c5d6b8510..273587eb52 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -63,9 +63,9 @@ For naga changelogs at or before v0.14.0. See [naga's changelog](naga/CHANGELOG.
 
 - Improve algorithm used by module compaction. By @jimblandy in [#4662](https://github.com/gfx-rs/wgpu/pull/4662).
 
-##### MSL-OUT
+- In Metal Shading Language output, fix issue where local variables were sometimes using variable names from previous functions.
 
-- Fix issue where local variables were sometimes using variable names from previous functions.
+- When reading GLSL, fix the argument types of the double-precision floating-point overloads of the `dot`, `reflect`, `distance`, and `ldexp` builtin functions. Correct the WGSL generated for constructing 64-bit floating-point matrices. Add tests for all the above. By @jimblandy in [#4684](https://github.com/gfx-rs/wgpu/pull/4684).
 
 ## v0.18.0 (2023-10-25)
 
diff --git a/naga/src/back/wgsl/writer.rs b/naga/src/back/wgsl/writer.rs
index 2a398e8845..cd9ae076f3 100644
--- a/naga/src/back/wgsl/writer.rs
+++ b/naga/src/back/wgsl/writer.rs
@@ -524,14 +524,14 @@ impl<W: Write> Writer<W> {
             TypeInner::Matrix {
                 columns,
                 rows,
-                width: _,
+                width,
             } => {
                 write!(
                     self.out,
-                    //TODO: Can matrix be other than f32?
-                    "mat{}x{}<f32>",
+                    "mat{}x{}<{}>",
                     back::vector_size_str(columns),
                     back::vector_size_str(rows),
+                    scalar_kind_str(crate::Scalar::float(width))
                 )?;
             }
             TypeInner::Pointer { base, space } => {
diff --git a/naga/src/front/glsl/builtins.rs b/naga/src/front/glsl/builtins.rs
index 0b01204dac..afe404a7eb 100644
--- a/naga/src/front/glsl/builtins.rs
+++ b/naga/src/front/glsl/builtins.rs
@@ -1246,18 +1246,14 @@ fn inject_common_builtin(
                     _ => unreachable!(),
                 };
 
-                let second_scalar = if fun == MacroCall::MathFunction(MathFunction::Ldexp) {
-                    Scalar {
-                        kind: Sk::Sint,
-                        width: float_width,
-                    }
-                } else {
-                    float_scalar
+                let second_scalar = match fun {
+                    MacroCall::MathFunction(MathFunction::Ldexp) => Scalar::I32,
+                    _ => float_scalar,
                 };
 
                 declaration
                     .overloads
-                    .push(module.add_builtin(vec![ty(Scalar::F32), ty(second_scalar)], fun))
+                    .push(module.add_builtin(vec![ty(float_scalar), ty(second_scalar)], fun))
             }
         }
         "transpose" => {
diff --git a/naga/tests/in/glsl/double-math-functions.frag b/naga/tests/in/glsl/double-math-functions.frag
new file mode 100644
index 0000000000..78f53f9ef6
--- /dev/null
+++ b/naga/tests/in/glsl/double-math-functions.frag
@@ -0,0 +1,34 @@
+#version 450
+
+void main() {
+    dvec4 a = dvec4(1.0);
+    dvec4 b = dvec4(2.0);
+    dmat4 m = dmat4(a, b, a, b);
+    int i = 5;
+
+    dvec4 ceilOut = ceil(a);
+    dvec4 roundOut = round(a);
+    dvec4 floorOut = floor(a);
+    dvec4 fractOut = fract(a);
+    dvec4 truncOut = trunc(a);
+    dvec4 absOut = abs(a);
+    dvec4 sqrtOut = sqrt(a);
+    dvec4 inversesqrtOut = inversesqrt(a);
+    dvec4 signOut = sign(a);
+    dmat4 transposeOut = transpose(m);
+    dvec4 normalizeOut = normalize(a);
+    double lengthOut = length(a);
+    double determinantOut = determinant(m);
+    double modOut = mod(a.x, b.x);
+    double dotOut = dot(a, b);
+    dvec4 maxOut = max(a, b);
+    dvec4 minOut = min(a, b);
+    dvec4 reflectOut = reflect(a, b);
+    dvec3 crossOut = cross(a.xyz, b.xyz);
+    double distanceOut = distance(a, b);
+    dvec4 stepOut = step(a, b);
+    double ldexpOut = ldexp(a.x, i);
+    double smoothStepScalar = smoothstep(0.0, 1.0, 0.5);
+    dvec4 smoothStepVector = smoothstep(dvec4(0.0), dvec4(1.0), dvec4(0.5));
+    dvec4 smoothStepMixed = smoothstep(0.0, 1.0, dvec4(0.5));
+}
diff --git a/naga/tests/out/wgsl/double-math-functions.frag.wgsl b/naga/tests/out/wgsl/double-math-functions.frag.wgsl
new file mode 100644
index 0000000000..d21d99f4de
--- /dev/null
+++ b/naga/tests/out/wgsl/double-math-functions.frag.wgsl
@@ -0,0 +1,107 @@
+fn main_1() {
+    var a: vec4<f64>;
+    var b: vec4<f64>;
+    var m: mat4x4<f64>;
+    var i: i32 = 5;
+    var ceilOut: vec4<f64>;
+    var roundOut: vec4<f64>;
+    var floorOut: vec4<f64>;
+    var fractOut: vec4<f64>;
+    var truncOut: vec4<f64>;
+    var absOut: vec4<f64>;
+    var sqrtOut: vec4<f64>;
+    var inversesqrtOut: vec4<f64>;
+    var signOut: vec4<f64>;
+    var transposeOut: mat4x4<f64>;
+    var normalizeOut: vec4<f64>;
+    var lengthOut: f64;
+    var determinantOut: f64;
+    var modOut: f64;
+    var dotOut: f64;
+    var maxOut: vec4<f64>;
+    var minOut: vec4<f64>;
+    var reflectOut: vec4<f64>;
+    var crossOut: vec3<f64>;
+    var distanceOut: f64;
+    var stepOut: vec4<f64>;
+    var ldexpOut: f64;
+    var smoothStepScalar: f64;
+    var smoothStepVector: vec4<f64>;
+    var smoothStepMixed: vec4<f64>;
+
+    a = vec4(f64(1.0));
+    b = vec4(f64(2.0));
+    let _e8 = a;
+    let _e9 = b;
+    let _e10 = a;
+    let _e11 = b;
+    m = mat4x4<f64>(vec4<f64>(_e8.x, _e8.y, _e8.z, _e8.w), vec4<f64>(_e9.x, _e9.y, _e9.z, _e9.w), vec4<f64>(_e10.x, _e10.y, _e10.z, _e10.w), vec4<f64>(_e11.x, _e11.y, _e11.z, _e11.w));
+    let _e37 = a;
+    ceilOut = ceil(_e37);
+    let _e41 = a;
+    roundOut = round(_e41);
+    let _e45 = a;
+    floorOut = floor(_e45);
+    let _e49 = a;
+    fractOut = fract(_e49);
+    let _e53 = a;
+    truncOut = trunc(_e53);
+    let _e57 = a;
+    absOut = abs(_e57);
+    let _e61 = a;
+    sqrtOut = sqrt(_e61);
+    let _e65 = a;
+    inversesqrtOut = inverseSqrt(_e65);
+    let _e69 = a;
+    signOut = sign(_e69);
+    let _e73 = m;
+    transposeOut = transpose(_e73);
+    let _e77 = a;
+    normalizeOut = normalize(_e77);
+    let _e81 = a;
+    lengthOut = length(_e81);
+    let _e85 = m;
+    determinantOut = determinant(_e85);
+    let _e88 = a;
+    let _e90 = b;
+    let _e92 = a;
+    let _e94 = b;
+    modOut = (_e92.x - (floor((_e92.x / _e94.x)) * _e94.x));
+    let _e103 = a;
+    let _e104 = b;
+    dotOut = dot(_e103, _e104);
+    let _e109 = a;
+    let _e110 = b;
+    maxOut = max(_e109, _e110);
+    let _e115 = a;
+    let _e116 = b;
+    minOut = min(_e115, _e116);
+    let _e121 = a;
+    let _e122 = b;
+    reflectOut = reflect(_e121, _e122);
+    let _e125 = a;
+    let _e127 = b;
+    let _e129 = a;
+    let _e131 = b;
+    crossOut = cross(_e129.xyz, _e131.xyz);
+    let _e137 = a;
+    let _e138 = b;
+    distanceOut = distance(_e137, _e138);
+    let _e143 = a;
+    let _e144 = b;
+    stepOut = step(_e143, _e144);
+    let _e147 = a;
+    let _e150 = a;
+    let _e152 = i;
+    ldexpOut = ldexp(_e150.x, _e152);
+    smoothStepScalar = f64(smoothstep(0.0, 1.0, 0.5));
+    smoothStepVector = smoothstep(vec4(f64(0.0)), vec4(f64(1.0)), vec4(f64(0.5)));
+    smoothStepMixed = smoothstep(vec4(f64(0.0)), vec4(f64(1.0)), vec4(f64(0.5)));
+    return;
+}
+
+@fragment 
+fn main() {
+    main_1();
+    return;
+}