diff --git a/src/common/mm_io.cpp b/src/common/mm_io.cpp
index 8de842474..07da869d5 100644
--- a/src/common/mm_io.cpp
+++ b/src/common/mm_io.cpp
@@ -32,6 +32,11 @@
 #include "common/strings/editing.h"
 #include "common/strings/parsing.h"
 
+union double_to_uint64_t {
+  uint64_t i;
+  double d;
+};
+
 #if !defined(SYS_WINDOWS)
 static std::string
 get_errno_msg() {
@@ -365,6 +370,14 @@ mm_io_c::read_uint64_be() {
   return get_uint64_be(buffer);
 }
 
+double
+mm_io_c::read_double() {
+  double_to_uint64_t d2ui;
+
+  d2ui.i = read_uint64_be();
+  return d2ui.d;
+}
+
 uint32_t
 mm_io_c::read(memory_cptr &buffer,
               size_t size,
@@ -436,6 +449,13 @@ mm_io_c::write_uint64_be(uint64_t value) {
   return write(&buffer, sizeof(uint64_t));
 }
 
+int
+mm_io_c::write_double(double value) {
+  double_to_uint64_t d2ui;
+  d2ui.d = value;
+  return write_uint64_be(d2ui.i);
+}
+
 size_t
 mm_io_c::write(const void *buffer,
                size_t size) {
diff --git a/src/common/mm_io.h b/src/common/mm_io.h
index 75b62708e..3f85fbb73 100644
--- a/src/common/mm_io.h
+++ b/src/common/mm_io.h
@@ -149,6 +149,7 @@ public:
   virtual uint32_t read_uint24_be();
   virtual uint32_t read_uint32_be();
   virtual uint64_t read_uint64_be();
+  virtual double read_double();
   virtual int write_uint8(unsigned char value);
   virtual int write_uint16_le(uint16_t value);
   virtual int write_uint32_le(uint32_t value);
@@ -156,6 +157,7 @@ public:
   virtual int write_uint16_be(uint16_t value);
   virtual int write_uint32_be(uint32_t value);
   virtual int write_uint64_be(uint64_t value);
+  virtual int write_double(double value);
   virtual void skip(int64 numbytes);
   virtual size_t write(const void *buffer, size_t size);
   virtual size_t write(std::string const &buffer) {