diff --git a/src/core/model/int64x64-128.h b/src/core/model/int64x64-128.h
index 2214992a4..4f7ee95a4 100644
--- a/src/core/model/int64x64-128.h
+++ b/src/core/model/int64x64-128.h
@@ -217,6 +217,12 @@ public:
     return *this;
   }
 
+  /** Explicit bool conversion. */
+  inline explicit operator bool () const
+  {
+    return (_v != 0);
+  }
+
   /**
    * Get this value as a double.
    *
diff --git a/src/core/model/int64x64-cairo.h b/src/core/model/int64x64-cairo.h
index ca2353578..3357b76dc 100644
--- a/src/core/model/int64x64-cairo.h
+++ b/src/core/model/int64x64-cairo.h
@@ -198,6 +198,12 @@ public:
     return *this;
   }
 
+  /** Explicit bool conversion. */
+  inline explicit operator bool () const
+  {
+    return (_v != 0);
+  }
+
   /**
    * Get this value as a double.
    *
diff --git a/src/core/model/int64x64-double.h b/src/core/model/int64x64-double.h
index 81e6cb591..5f653b2ea 100644
--- a/src/core/model/int64x64-double.h
+++ b/src/core/model/int64x64-double.h
@@ -112,7 +112,7 @@ public:
     : _v (v)
   {}
   inline int64x64_t (long long int v)
-    : _v (static_cast<double> (v))
+    : _v (static_cast<long double> (v))
   {}
   inline int64x64_t (unsigned int v)
     : _v (v)
@@ -121,7 +121,7 @@ public:
     : _v (v)
   {}
   inline int64x64_t (unsigned long long int v)
-    : _v (static_cast<double> (v))
+    : _v (static_cast<long double> (v))
   {}
   /**@}*/
   /**
@@ -161,6 +161,12 @@ public:
     return *this;
   }
 
+  /** Explicit bool conversion. */
+  inline explicit operator bool () const
+  {
+    return (_v != 0);
+  }
+
   /**
    * Get this value as a double.
    *