diff --git a/testing/.gitignore b/testing/.gitignore
new file mode 100644
index 00000000..402eee67
--- /dev/null
+++ b/testing/.gitignore
@@ -0,0 +1 @@
+regression-conf.php.dynamic.per-test
diff --git a/testing/dav_test b/testing/dav_test
index cefea0ac..2b1c4c00 100755
--- a/testing/dav_test
+++ b/testing/dav_test
@@ -90,6 +90,14 @@ my $request_id_file = "$save_location/$case.request_id";
 open(my $REQUEST_ID_FILE, "> $request_id_file")
     || die "Failed to open $request_id_file for writing";
 
+# Allow for application configuration per test file. Ensure the file we
+# manage is empty in case the previous test was aborted.
+my $dynamic_app_conf_file = 'regression-conf.php.dynamic.per-test';
+if (-f $dynamic_app_conf_file) {
+    unlink $dynamic_app_conf_file
+        || die "Failed to remove $dynamic_app_conf_file\n";
+}
+
 my $datafile = $testdef;
 $datafile =~ s{\.test$}{};
 push @arguments, "--header", 'X-DAViCal-Testcase: '.$datafile;
@@ -98,13 +106,14 @@ $datafile .= '.data';
 my $state = "";
 my $data_binary;
 
-my $sql_variable = "";
+my $sql_variable  = "";
 my $sql_statement = "";
+my $sql_values    = {};
 my $perl_code = "";
-my $sql_values = {};
-my $queries = ();
+my $app_conf  = "";
+my $queries   = ();
 my $replacements = ();
-my $line_number = 0;
+my $line_number  = 0;
 
 
 open( TEST, '<', $testdef ) or die "Can't open '$testdef'";
@@ -119,7 +128,7 @@ while( <TEST> ) {
   }
 
   if ( $state ne "" ) {
-    $line =~ /^BEGIN(DATA|PERL)/ && do {
+    $line =~ /^BEGIN(?!:)/ && do {
       print "Found a new BEGIN line, while still processing a previous one. Line number: $line_number\n";
       exit 0;
     };
@@ -141,6 +150,9 @@ while( <TEST> ) {
           exit 0;
         }
       }
+      elsif ( $state eq "APPCONF" ) {
+        write_app_conf($app_conf);
+      }
       $state = "";
     }
     elsif ( $state eq "DATA" ) {
@@ -152,6 +164,9 @@ while( <TEST> ) {
     elsif ( $state eq "PERL" ) {
       $perl_code .= $line;
     }
+    elsif ( $state eq "APPCONF" ) {
+      $app_conf .= $line;
+    }
     next;
   }
 
@@ -226,6 +241,11 @@ while( <TEST> ) {
     $state = "PERL";
   };
 
+  $line =~ /^BEGINAPPCONF\s*$/ && do {
+    $app_conf = "";
+    $state = "APPCONF";
+  };
+
   $line =~ /^(?:BEGIN)?GETSQL\s*=\s*(\S.*)$/ && do {
     $sql_variable = $1;
     $sql_statement = "";
@@ -237,6 +257,26 @@ while( <TEST> ) {
     $state = "DOSQL";
   };
 
+  $line =~ /^\s*APPCONF\s*=\s*(\S.*)$/ && do {
+      my $basename = $1;
+      my $test_app_conf_file;
+
+      if ( -e "tests/$suite/$basename.appconf" ) {
+          $test_app_conf_file="tests/$suite/$basename.appconf";
+      }
+      elsif ( -e "tests/$suite/$basename" ) {
+          $test_app_conf_file="tests/$suite/$basename";
+      }
+
+      if (! defined $test_app_conf_file) {
+          die "Can't find app conf file $basename or $basename.appconf";
+      }
+
+      copy $test_app_conf_file, $dynamic_app_conf_file
+          || die "Failed to copy $test_app_conf_file to $dynamic_app_conf_file: $!\n";
+  };
+
+
   $line =~ /^REPLACE\s*=\s*(\S)(.*)$/ && do {
     my $separator = $1;
     $2 =~ /^([^$separator]*)$separator([^$separator]*)$separator$/ && do {
@@ -506,6 +546,22 @@ sub webui_login {
     return $mech;
 }
 
+=item write_app_conf()
+
+Write per test configuration entries to the DAViCal regression test server
+configuration.
+
+=cut
+
+sub write_app_conf {
+    my $content = shift;
+
+    # We may wany to append extra content to a common file.
+    open(my $FILE, ">> $dynamic_app_conf_file")
+        || die "Failed to open $dynamic_app_conf_file for writing";
+    print $FILE $content;
+}
+
 
 sub usage {
   print <<EOERROR ;
@@ -556,6 +612,16 @@ BEGINPERL
 my \$variable = 'foo';
 ENDPERL
 
+# Dynamically add content to the DAViCal configuration file for this test.
+# Allows ad-hoc config changes for tests. See also APPCONF. If APPCONF isn't
+# used, then you must start this with "<?php" as below. If APPCONF is used,
+# then it must start with "<?php".
+BEGINAPPCONF
+<?php
+
+\$valid_php = "in here";
+ENDAPPCONF
+
 REPLACE=/pattern/replacement/
 =================================================
 
@@ -566,6 +632,10 @@ HEAD     Whether to include the headers in the recorded response
 VERBOSE  Whether to provide the full request / response headers.
 DATA     The name of a different test in this suite to use data from.
 REPLACE  A perl regex replacement to post-process the result through.
+APPCONF  A file that will be insert into the DAViCal config file. This is
+         inserted first, before any content in BEGINAPPCONF/ENDAPPCONF to
+         allow a common config file for a set of tests, but also to allow
+         for individual test overrides.
 
 Additionally, if a file 'tests/<testsuite>/<testname>.data' exists
 the contents of that file will be sent in the body of the request.
diff --git a/testing/regression-conf.php.example b/testing/regression-conf.php.example
index de2348e3..00d20355 100644
--- a/testing/regression-conf.php.example
+++ b/testing/regression-conf.php.example
@@ -69,4 +69,6 @@
     'cal._domainkey.caldav' => 'v=DKIM1; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEArTRqr/W5wSlxDKthes0Bz2fIkukLOu0tNIbxO9GpsjgaE3juPnl9XlkMxvkGQ5k7NTy2yRIYDFqDzT150MiMLsIbOnXlOZVizlM8MXe65do6BNCnjNZRNj30pEHirhJsQf0eEc9+AY1qDbC2axqd1Nf8MNl0bJ58O0ZCPnzdDNxsWp16midWoj0uceonpg1qxp7kYD2CC5/WcrsBHc8Lt3y2N9X4pamAvd0fAfVXYrzLSVvmc1b09yEq3weT4R4Jiizjb7UPPZCyarDDOUKfjcBsPCJtBDv7al6easoCUvHviJKy48bmcFcgnyL1FfKVdIaKlyb3nLj9dFTFm/tdTQIDAQAB',
   );
 
+  // Allow dynamic configuration of application by tests.
+  include 'regression-conf.php.dynamic.per-test';
 ?>