diff --git a/C4/Context.pm b/C4/Context.pm
index 1bf23c23ce..4ff47af54a 100644
--- a/C4/Context.pm
+++ b/C4/Context.pm
@@ -615,7 +615,7 @@ sub set_preference {
     $value = 0 if ( $type && $type eq 'YesNo' && $value eq '' );
 
     # force explicit protocol on OPACBaseURL
-    if ( $variable eq 'opacbaseurl' && substr( $value, 0, 4 ) !~ /http/ ) {
+    if ( $variable eq 'opacbaseurl' && $value && substr( $value, 0, 4 ) !~ /http/ ) {
         $value = 'http://' . $value;
     }
 
diff --git a/t/db_dependent/Context.t b/t/db_dependent/Context.t
index b5a050faf6..bce0cef209 100755
--- a/t/db_dependent/Context.t
+++ b/t/db_dependent/Context.t
@@ -39,6 +39,10 @@ C4::Context->clear_syspref_cache();
 $OPACBaseURL = C4::Context->preference('OPACBaseURL');
 is($OPACBaseURL,'http://junk2','OPACBaseURL saved with http:// as specified');
 
+C4::Context->set_preference('OPACBaseURL', '');
+$OPACBaseURL = C4::Context->preference('OPACBaseURL');
+is($OPACBaseURL,'','OPACBaseURL saved empty as specified');
+
 C4::Context->set_preference('SillyPreference','random');
 C4::Context->clear_syspref_cache();
 my $SillyPeference = C4::Context->preference('SillyPreference');