diff --git a/src/Controllers/ApiController.php b/src/Controllers/ApiController.php
index f4ed5f2..368cd40 100644
--- a/src/Controllers/ApiController.php
+++ b/src/Controllers/ApiController.php
@@ -14,7 +14,8 @@ class ApiController implements ControllerInterface
     public function show( ZermeloReport $report )
     {
         $presenter = new CardPresenter( $report );
-        $presenter->setApiPrefix( api_prefix() );
+	$api_prefix = trim( config("zermelo.URI_API_PREFIX"), "/ " );
+        $presenter->setApiPrefix( $api_prefix );
         $presenter->setReportPath( config('zermelobladecard.TABULAR_URI_PREFIX') );
         $presenter->setSummaryPath( config('zermelobladecard.SUMMARY_URI_PREFIX') );
         $cache = new DatabaseCache( $report );
@@ -24,7 +25,8 @@ public function show( ZermeloReport $report )
 
     public function prefix() : string
     {
-        $prefix = api_prefix()."/".config('zermelobladecard.TABULAR_URI_PREFIX', "" );
+	$api_prefix = trim( config("zermelo.URI_API_PREFIX"), "/ " );
+        $prefix = $api_prefix."/".config('zermelobladecard.TABULAR_URI_PREFIX', "" );
         return $prefix;
     }
 }
diff --git a/src/Controllers/SummaryController.php b/src/Controllers/SummaryController.php
index dc1ada0..439a118 100644
--- a/src/Controllers/SummaryController.php
+++ b/src/Controllers/SummaryController.php
@@ -18,7 +18,8 @@ public function show( ZermeloReport $report )
 
     public function prefix() : string
     {
-        $prefix = api_prefix()."/".config('zermelobladecard.SUMMARY_URI_PREFIX', "" );
+	$api_prefix = trim( config("zermelo.URI_API_PREFIX"), "/ " );
+        $prefix = $api_prefix."/".config('zermelobladecard.SUMMARY_URI_PREFIX', "" );
         return $prefix;
     }
 }
diff --git a/src/Controllers/WebController.php b/src/Controllers/WebController.php
index 72b1de4..d1677ee 100644
--- a/src/Controllers/WebController.php
+++ b/src/Controllers/WebController.php
@@ -14,7 +14,8 @@ public function show( ZermeloReport $report )
     {
         $presenter = new CardPresenter( $report );
 
-        $presenter->setApiPrefix( api_prefix() );
+	$api_prefix = trim( config("zermelo.URI_API_PREFIX"), "/ " );
+        $presenter->setApiPrefix( $api_prefix );
         $presenter->setReportPath( config('zermelobladecard.TABULAR_URI_PREFIX', '') );
         $presenter->setSummaryPath( config('zermelobladecard.SUMMARY_URI_PREFIX', '') );