diff --git a/CHANGES.current b/CHANGES.current
index 81ea4ac7e..1695cb216 100644
--- a/CHANGES.current
+++ b/CHANGES.current
@@ -5,6 +5,10 @@ See the RELEASENOTES file for a summary of changes in each release.
 Version 3.0.11 (in progress)
 ============================
 
+2016-12-18: ezralanglois 
+            [Python, Ruby, Octave] Memory leak fix on error in std::pair wrappers.
+            Issue https://github.com/swig/swig/pull/851
+
 2016-12-16: bcaine
             [Guile] Patch #744 Added support for Guile's native pointer functionality
 
diff --git a/Lib/octave/std_pair.i b/Lib/octave/std_pair.i
index a06498bf2..2f3d4dfa4 100644
--- a/Lib/octave/std_pair.i
+++ b/Lib/octave/std_pair.i
@@ -69,12 +69,16 @@
 	  value_type *vp = %new_instance(std::pair<T,U>);
 	  T *pfirst = &(vp->first);
 	  int res1 = swig::asval(first, pfirst);
-	  if (!SWIG_IsOK(res1))
+	  if (!SWIG_IsOK(res1)) {
+	    %delete(vp);
 	    return res1;
+	  }
 	  U *psecond = &(vp->second);
 	  int res2 = swig::asval(second, psecond);
-	  if (!SWIG_IsOK(res2))
+	  if (!SWIG_IsOK(res2)) {
+	    %delete(vp);
 	    return res2;
+	  }
 	  *val = vp;
 	  return SWIG_AddNewMask(res1 > res2 ? res1 : res2);
 	} else {
diff --git a/Lib/python/std_pair.i b/Lib/python/std_pair.i
index 0fcd4f082..172572bff 100644
--- a/Lib/python/std_pair.i
+++ b/Lib/python/std_pair.i
@@ -31,7 +31,7 @@
 	  int res2 = swig::asval((PyObject*)second, psecond);
 	  if (!SWIG_IsOK(res2)) return res2;
 	  return res1 > res2 ? res1 : res2;
-	}	
+	}
       }
 
       static int asval(PyObject *obj, std::pair<T,U> *val) {
@@ -68,15 +68,13 @@
 	  value_type *vp = %new_instance(std::pair<T,U>);
 	  T *pfirst = &(vp->first);
 	  int res1 = swig::asval((PyObject*)first, pfirst);
-	  if (!SWIG_IsOK(res1))
-	  {
+	  if (!SWIG_IsOK(res1)) {
 	    %delete(vp);
 	    return res1;
 	  }
 	  U *psecond = &(vp->second);
 	  int res2 = swig::asval((PyObject*)second, psecond);
-	  if (!SWIG_IsOK(res2))
-	  {
+	  if (!SWIG_IsOK(res2)) {
 	    %delete(vp);
 	    return res2;
 	  }
@@ -90,7 +88,7 @@
 	  int res2 = swig::asval((PyObject*)second, psecond);
 	  if (!SWIG_IsOK(res2)) return res2;
 	  return res1 > res2 ? res1 : res2;
-	}	
+	}
       }
 
       static int asptr(PyObject *obj, std::pair<T,U> **val) {
diff --git a/Lib/ruby/std_pair.i b/Lib/ruby/std_pair.i
index 5bea67c7c..38a4ffb9b 100644
--- a/Lib/ruby/std_pair.i
+++ b/Lib/ruby/std_pair.i
@@ -31,7 +31,7 @@
 	  int res2 = swig::asval((VALUE)second, psecond);
 	  if (!SWIG_IsOK(res2)) return res2;
 	  return res1 > res2 ? res1 : res2;
-	}	
+	}
       }
 
       static int asval(VALUE obj, std::pair<T,U> *val) {
@@ -63,10 +63,16 @@
 	  value_type *vp = %new_instance(std::pair<T,U>);
 	  T *pfirst = &(vp->first);
 	  int res1 = swig::asval((VALUE)first, pfirst);
-	  if (!SWIG_IsOK(res1)) return res1;
+	  if (!SWIG_IsOK(res1)) {
+	    %delete(vp);
+	    return res1;
+	  }
 	  U *psecond = &(vp->second);
 	  int res2 = swig::asval((VALUE)second, psecond);
-	  if (!SWIG_IsOK(res2)) return res2;
+	  if (!SWIG_IsOK(res2)) {
+	    %delete(vp);
+	    return res2;
+	  }
 	  *val = vp;
 	  return SWIG_AddNewMask(res1 > res2 ? res1 : res2);
 	} else {
@@ -77,7 +83,7 @@
 	  int res2 = swig::asval((VALUE)second, psecond);
 	  if (!SWIG_IsOK(res2)) return res2;
 	  return res1 > res2 ? res1 : res2;
-	}	
+	}
       }
 
       static int asptr(VALUE obj, std::pair<T,U> **val) {