diff --git a/Misc/NEWS b/Misc/NEWS
index 9ef096035d5..03267edef62 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -215,6 +215,8 @@ Extension Modules
 Build
 -----
 
+- Issue #3920: Define _BSD_SOURCE on OpenBSD 4.4.
+
 - Issue #7661: Allow ctypes to be built from a non-ASCII directory path.
   Patch by Florent Xicluna.
 
diff --git a/configure b/configure
index 51175d25fec..f678a1e277e 100755
--- a/configure
+++ b/configure
@@ -1,5 +1,5 @@
 #! /bin/sh
-# From configure.in Revision: 78151 .
+# From configure.in Revision: 78155 .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.61 for python 2.6.
 #
@@ -2118,6 +2118,16 @@ case $ac_sys_system/$ac_sys_release in
     # also defined. This can be overridden by defining _BSD_SOURCE
     # As this has a different meaning on Linux, only define it on OpenBSD
 
+cat >>confdefs.h <<\_ACEOF
+#define _BSD_SOURCE 1
+_ACEOF
+
+    ;;
+  OpenBSD/4.[4])
+    # OpenBSD undoes our definition of __BSD_VISIBLE if _XOPEN_SOURCE is
+    # also defined. This can be overridden by defining _BSD_SOURCE
+    # As this has a different meaning on Linux, only define it on OpenBSD
+
 cat >>confdefs.h <<\_ACEOF
 #define _BSD_SOURCE 1
 _ACEOF
@@ -3876,7 +3886,7 @@ else
   { echo "$as_me:$LINENO: result: no" >&5
 echo "${ECHO_T}no" >&6; }
 fi
-rm -f -r conftest*
+rm -f conftest*
 
 
 
@@ -5415,7 +5425,7 @@ if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
 else
   ac_cv_header_stdc=no
 fi
-rm -f -r conftest*
+rm -f conftest*
 
 fi
 
@@ -5436,7 +5446,7 @@ if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
 else
   ac_cv_header_stdc=no
 fi
-rm -f -r conftest*
+rm -f conftest*
 
 fi
 
@@ -6534,7 +6544,7 @@ _ACEOF
 
 
 fi
-rm -f -r conftest*
+rm -f conftest*
 
 { echo "$as_me:$LINENO: result: $was_it_defined" >&5
 echo "${ECHO_T}$was_it_defined" >&6; }
@@ -7064,7 +7074,7 @@ if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
 else
   ac_cv_type_uid_t=no
 fi
-rm -f -r conftest*
+rm -f conftest*
 
 fi
 { echo "$as_me:$LINENO: result: $ac_cv_type_uid_t" >&5
@@ -14189,7 +14199,7 @@ if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
 else
   unistd_defines_pthreads=no
 fi
-rm -f -r conftest*
+rm -f conftest*
 
     { echo "$as_me:$LINENO: result: $unistd_defines_pthreads" >&5
 echo "${ECHO_T}$unistd_defines_pthreads" >&6; }
@@ -15803,7 +15813,7 @@ if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
   $EGREP "yes" >/dev/null 2>&1; then
   ipv6type=$i
 fi
-rm -f -r conftest*
+rm -f conftest*
 
 			;;
 		kame)
@@ -15826,7 +15836,7 @@ if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
 				ipv6libdir=/usr/local/v6/lib
 				ipv6trylibc=yes
 fi
-rm -f -r conftest*
+rm -f conftest*
 
 			;;
 		linux-glibc)
@@ -15847,7 +15857,7 @@ if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
   ipv6type=$i;
 				ipv6trylibc=yes
 fi
-rm -f -r conftest*
+rm -f conftest*
 
 			;;
 		linux-inet6)
@@ -15885,7 +15895,7 @@ if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
 				ipv6lib=inet6;
 				ipv6libdir=/usr/local/v6/lib
 fi
-rm -f -r conftest*
+rm -f conftest*
 
 			;;
 		v6d)
@@ -15908,7 +15918,7 @@ if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
 				ipv6libdir=/usr/local/v6/lib;
 				BASECFLAGS="-I/usr/local/v6/include $BASECFLAGS"
 fi
-rm -f -r conftest*
+rm -f conftest*
 
 			;;
 		zeta)
@@ -15930,7 +15940,7 @@ if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
 				ipv6lib=inet6;
 				ipv6libdir=/usr/local/v6/lib
 fi
-rm -f -r conftest*
+rm -f conftest*
 
 			;;
 		esac
@@ -23705,7 +23715,7 @@ cat >>confdefs.h <<\_ACEOF
 _ACEOF
 
 fi
-rm -f -r conftest*
+rm -f conftest*
 
   cat >conftest.$ac_ext <<_ACEOF
 /* confdefs.h.  */
@@ -23724,7 +23734,7 @@ cat >>confdefs.h <<\_ACEOF
 _ACEOF
 
 fi
-rm -f -r conftest*
+rm -f conftest*
 
 fi
 
@@ -23994,7 +24004,7 @@ cat >>confdefs.h <<\_ACEOF
 _ACEOF
 
 fi
-rm -f -r conftest*
+rm -f conftest*
 
 fi
 
diff --git a/configure.in b/configure.in
index 635dc70b2e5..66da672cbef 100644
--- a/configure.in
+++ b/configure.in
@@ -285,6 +285,12 @@ case $ac_sys_system/$ac_sys_release in
     # As this has a different meaning on Linux, only define it on OpenBSD
     AC_DEFINE(_BSD_SOURCE, 1, [Define on OpenBSD to activate all library features])
     ;;
+  OpenBSD/4.@<:@4@:>@)
+    # OpenBSD undoes our definition of __BSD_VISIBLE if _XOPEN_SOURCE is
+    # also defined. This can be overridden by defining _BSD_SOURCE
+    # As this has a different meaning on Linux, only define it on OpenBSD
+    AC_DEFINE(_BSD_SOURCE, 1, [Define on OpenBSD to activate all library features])
+    ;;
   # Defining _XOPEN_SOURCE on NetBSD version prior to the introduction of
   # _NETBSD_SOURCE disables certain features (eg. setgroups). Reported by
   # Marc Recht