diff --git a/src/serialize.h b/src/serialize.h
--- a/src/serialize.h
+++ b/src/serialize.h
@@ -137,36 +137,32 @@
     return le64toh(obj);
 }
 inline uint64_t ser_double_to_uint64(double x) {
-    union {
-        double x;
-        uint64_t y;
-    } tmp;
-    tmp.x = x;
-    return tmp.y;
+    uint64_t tmp;
+    std::memcpy(&tmp, &x, sizeof(x));
+    static_assert(sizeof(tmp) == sizeof(x),
+                  "double and uint64_t assumed to have the same size");
+    return tmp;
 }
 inline uint32_t ser_float_to_uint32(float x) {
-    union {
-        float x;
-        uint32_t y;
-    } tmp;
-    tmp.x = x;
-    return tmp.y;
+    uint32_t tmp;
+    std::memcpy(&tmp, &x, sizeof(x));
+    static_assert(sizeof(tmp) == sizeof(x),
+                  "float and uint32_t assumed to have the same size");
+    return tmp;
 }
 inline double ser_uint64_to_double(uint64_t y) {
-    union {
-        double x;
-        uint64_t y;
-    } tmp;
-    tmp.y = y;
-    return tmp.x;
+    double tmp;
+    std::memcpy(&tmp, &y, sizeof(y));
+    static_assert(sizeof(tmp) == sizeof(y),
+                  "double and uint64_t assumed to have the same size");
+    return tmp;
 }
 inline float ser_uint32_to_float(uint32_t y) {
-    union {
-        float x;
-        uint32_t y;
-    } tmp;
-    tmp.y = y;
-    return tmp.x;
+    float tmp;
+    std::memcpy(&tmp, &y, sizeof(y));
+    static_assert(sizeof(tmp) == sizeof(y),
+                  "float and uint32_t assumed to have the same size");
+    return tmp;
 }
 
 /////////////////////////////////////////////////////////////////