Index: js/src/old-configure.in
--- js/src/old-configure.in.orig
+++ js/src/old-configure.in
@@ -486,11 +486,18 @@ case "$target" in
     ;;
 
 *-openbsd*)
+    DLL_SUFFIX=".so.$SO_VERSION"
     DSO_PIC_CFLAGS='-fPIC'
     DSO_LDOPTS='-shared -fPIC'
     if test "$LIBRUNPATH"; then
 	DSO_LDOPTS="-R$LIBRUNPATH $DSO_LDOPTS"
     fi
+    if test "$GNU_LD"; then
+        # Don't allow undefined symbols in libraries
+        DSO_LDOPTS="$DSO_LDOPTS -Wl,-z,defs"
+    fi
+    MKSHLIB='$(CXX) $(CXXFLAGS) $(DSO_PIC_CFLAGS) $(DSO_LDOPTS) -o $@'
+    MKCSHLIB='$(CC) $(CFLAGS) $(DSO_PIC_CFLAGS) $(DSO_LDOPTS) -o $@'
     ;;
 
 *-solaris*)