diff --git a/README.md b/README.md
index 53a0e31..633a92d 100644
--- a/README.md
+++ b/README.md
@@ -1296,8 +1296,9 @@ vec<T, Size> rsqrt(const vec<T, Size>& xs);
 #### Scalar
 
 ```cpp
-template < arithmetic T >
-T dot(T x, T y);
+template < arithmetic T, arithmetic U
+         , arithmetic V = decltype(declval<T>() * declval<U>()) >
+V dot(T x, U y);
 
 template < arithmetic T >
 T length(T x);
@@ -1333,8 +1334,9 @@ T refract(T i, T n, T eta);
 #### Vector
 
 ```cpp
-template < typename T, size_t Size >
-T dot(const vec<T, Size>& xs, const vec<T, Size>& ys);
+template < typename T, typename U, size_t Size
+         , typename V = decltype(declval<T>() * declval<U>()) >
+V dot(const vec<T, Size>& xs, const vec<U, Size>& ys);
 
 template < typename T, size_t Size >
 T length(const vec<T, Size>& xs);
@@ -1354,11 +1356,13 @@ T distance(const vec<T, Size>& xs, const vec<T, Size>& ys);
 template < typename T, size_t Size >
 T distance2(const vec<T, Size>& xs, const vec<T, Size>& ys);
 
-template < typename T >
-T cross(const vec<T, 2>& xs, const vec<T, 2>& ys);
+template < typename T, typename U
+         , typename V = decltype(declval<T>() * declval<U>()) >
+V cross(const vec<T, 2>& xs, const vec<U, 2>& ys);
 
-template < typename T >
-vec<T, 3> cross(const vec<T, 3>& xs, const vec<T, 3>& ys);
+template < typename T, typename U
+         , typename V = decltype(declval<T>() * declval<U>()) >
+vec<V, 3> cross(const vec<T, 3>& xs, const vec<U, 3>& ys);
 
 template < typename T, size_t Size >
 vec<T, Size> normalize(const vec<T, Size>& xs);
@@ -1376,8 +1380,11 @@ vec<T, Size> refract(const vec<T, Size>& i, const vec<T, Size>& n, T eta);
 #### Quaternion
 
 ```cpp
-template < typename T >
-T dot(const qua<T>& xs, const qua<T>& ys);
+template < typename T, typename U
+         , typename V = decltype(dot(
+             declval<vec<T, 4>>(),
+             declval<vec<U, 4>>())) >
+V dot(const qua<T>& xs, const qua<U>& ys);
 
 template < typename T >
 T length(const qua<T>& xs);
diff --git a/headers/vmath.hpp/vmath_fun.hpp b/headers/vmath.hpp/vmath_fun.hpp
index 8da26fc..f155291 100644
--- a/headers/vmath.hpp/vmath_fun.hpp
+++ b/headers/vmath.hpp/vmath_fun.hpp
@@ -305,10 +305,11 @@ namespace vmath_hpp
 
 namespace vmath_hpp
 {
-    template < typename T >
-    [[nodiscard]] std::enable_if_t<std::is_arithmetic_v<T>, T>
-    constexpr dot(T x, T y) noexcept {
-        return x * y;
+    template < typename T, typename U
+             , typename V = decltype(std::declval<T>() * std::declval<U>()) >
+    [[nodiscard]] std::enable_if_t<std::is_arithmetic_v<V>, V>
+    constexpr dot(T x, U y) noexcept {
+        return { x * y };
     }
 
     template < typename T >
diff --git a/headers/vmath.hpp/vmath_qua_fun.hpp b/headers/vmath.hpp/vmath_qua_fun.hpp
index efb03ea..3b3ef2b 100644
--- a/headers/vmath.hpp/vmath_qua_fun.hpp
+++ b/headers/vmath.hpp/vmath_qua_fun.hpp
@@ -249,8 +249,11 @@ namespace vmath_hpp
 
 namespace vmath_hpp
 {
-    template < typename T >
-    [[nodiscard]] constexpr T dot(const qua<T>& xs, const qua<T>& ys) {
+    template < typename T, typename U
+             , typename V = decltype(dot(
+                 std::declval<vec<T, 4>>(),
+                 std::declval<vec<U, 4>>())) >
+    [[nodiscard]] constexpr V dot(const qua<T>& xs, const qua<U>& ys) {
         return dot(vec{xs}, vec{ys});
     }
 
diff --git a/headers/vmath.hpp/vmath_vec_fun.hpp b/headers/vmath.hpp/vmath_vec_fun.hpp
index 69c3c6e..6a194f5 100644
--- a/headers/vmath.hpp/vmath_vec_fun.hpp
+++ b/headers/vmath.hpp/vmath_vec_fun.hpp
@@ -775,11 +775,12 @@ namespace vmath_hpp
 
 namespace vmath_hpp
 {
-    template < typename T, std::size_t Size >
-    [[nodiscard]] constexpr T dot(const vec<T, Size>& xs, const vec<T, Size>& ys) {
-        return fold_join([](T acc, T x, T y){
+    template < typename T, typename U, std::size_t Size
+             , typename V = decltype(std::declval<T>() * std::declval<U>()) >
+    [[nodiscard]] constexpr V dot(const vec<T, Size>& xs, const vec<U, Size>& ys) {
+        return fold_join([](V acc, T x, U y){
             return acc + (x * y);
-        }, T{0}, xs, ys);
+        }, V{0}, xs, ys);
     }
 
     template < typename T, std::size_t Size >
@@ -812,13 +813,15 @@ namespace vmath_hpp
         return length2(ys - xs);
     }
 
-    template < typename T >
-    [[nodiscard]] constexpr T cross(const vec<T, 2>& xs, const vec<T, 2>& ys) {
-        return xs.x * ys.y - xs.y * ys.x;
+    template < typename T, typename U
+             , typename V = decltype(std::declval<T>() * std::declval<U>()) >
+    [[nodiscard]] constexpr V cross(const vec<T, 2>& xs, const vec<U, 2>& ys) {
+        return { xs.x * ys.y - xs.y * ys.x };
     }
 
-    template < typename T >
-    [[nodiscard]] constexpr vec<T, 3> cross(const vec<T, 3>& xs, const vec<T, 3>& ys) {
+    template < typename T, typename U
+             , typename V = decltype(std::declval<T>() * std::declval<U>()) >
+    [[nodiscard]] constexpr vec<V, 3> cross(const vec<T, 3>& xs, const vec<U, 3>& ys) {
         return {
             xs.y * ys.z - xs.z * ys.y,
             xs.z * ys.x - xs.x * ys.z,
diff --git a/untests/vmath_fun_tests.cpp b/untests/vmath_fun_tests.cpp
index 9903781..4bb37e9 100644
--- a/untests/vmath_fun_tests.cpp
+++ b/untests/vmath_fun_tests.cpp
@@ -126,7 +126,9 @@ TEST_CASE("vmath/fun") {
         STATIC_CHECK(distance2(5.f, 10.f) == uapprox(25.f));
         STATIC_CHECK(distance2(-5.f, -10.f) == uapprox(25.f));
 
-        STATIC_CHECK(dot(2.f, 5.f) == uapprox(10.f));
+        STATIC_CHECK(dot(2, 5) == uapprox(10));
+        STATIC_CHECK(dot(2, 5.f) == uapprox(10.f));
+
         STATIC_CHECK(normalize(0.5f) == uapprox(1.f));
 
         STATIC_CHECK(faceforward(1.f, 2.f, 3.f) == uapprox(-1.f));
diff --git a/untests/vmath_qua_fun_tests.cpp b/untests/vmath_qua_fun_tests.cpp
index 80bb33e..b65d8e9 100644
--- a/untests/vmath_qua_fun_tests.cpp
+++ b/untests/vmath_qua_fun_tests.cpp
@@ -132,6 +132,7 @@ TEST_CASE("vmath/qua_fun") {
 
     SUBCASE("Geometric Functions") {
         STATIC_CHECK(dot(qua(1,2,3,4),qua(3,4,5,6)) == 50);
+        STATIC_CHECK(dot(qfloat(1,2,3,4),qdouble(3,4,5,6)) == uapprox(50.0));
 
         CHECK(length(qfloat(10.f,0.f,0.f,0.f)) == uapprox(10.f));
         CHECK(length(qfloat(-10.f,0.f,0.f,0.f)) == uapprox(10.f));
diff --git a/untests/vmath_vec_fun_tests.cpp b/untests/vmath_vec_fun_tests.cpp
index 262f1ec..53df1de 100644
--- a/untests/vmath_vec_fun_tests.cpp
+++ b/untests/vmath_vec_fun_tests.cpp
@@ -271,8 +271,17 @@ TEST_CASE("vmath/vec_fun") {
         STATIC_CHECK(distance2(float2(-5.f,0.f), float2(-10.f,0.f)) == uapprox(25.f));
 
         STATIC_CHECK(dot(int2(1,2),int2(3,4)) == 11);
+        STATIC_CHECK(dot(int2(1,2),float2(3,4)) == uapprox(11.f));
+        STATIC_CHECK(dot(float2(3,4),int2(1,2)) == uapprox(11.f));
+
         STATIC_CHECK(cross(int2(1,0),int2(0,1)) == 1);
+        STATIC_CHECK(cross(int2(1,0),float2(0,1)) == uapprox(1.f));
+        STATIC_CHECK(cross(float2(0,1),int2(1,0)) == uapprox(-1.f));
+
         STATIC_CHECK(cross(int3(1,0,0),int3(0,1,0)) == int3(0,0,1));
+        STATIC_CHECK(cross(int3(1,0,0),float3(0,1,0)) == uapprox3(0.f,0.f,1.f));
+        STATIC_CHECK(cross(float3(0,1,0),int3(1,0,0)) == uapprox3(0.f,0.f,-1.f));
+
         CHECK(normalize(float2(0.5f,0.f)).x == uapprox(1.f));
 
         STATIC_CHECK(faceforward(float2(1.f), float2(2.f), float2(3.f)).x == uapprox(-1.f));