diff --git a/api.php b/api.php
index 0d2312a7eab..554c2726bc1 100644
--- a/api.php
+++ b/api.php
@@ -70,10 +70,21 @@ $wgTitle = Title::makeTitle( NS_MAIN, 'API' );
 $processor = new ApiMain( RequestContext::getMain(), $wgEnableWriteAPI );
 
 // Last chance hook before executing the API
-wfRunHooks( 'ApiBeforeMain', array( &$processor ) );
+try {
+	wfRunHooks( 'ApiBeforeMain', array( &$processor ) );
+	if ( !$processor instanceof ApiMain ) {
+		throw new MWException( 'ApiBeforMain hook set $processor to a non-ApiMain class' );
+	}
+} catch ( Exception $e ) {
+	// Crap. Try to report the exception in API format to be friendly to clients.
+	ApiMain::handleApiBeforeMainException( $e );
+	$processor = false;
+}
 
 // Process data & print results
-$processor->execute();
+if ( $processor ) {
+	$processor->execute();
+}
 
 if ( function_exists( 'fastcgi_finish_request' ) ) {
 	fastcgi_finish_request();
@@ -97,11 +108,15 @@ if ( $wgAPIRequestLog ) {
 		$_SERVER['HTTP_USER_AGENT']
 	);
 	$items[] = $wgRequest->wasPosted() ? 'POST' : 'GET';
-	$module = $processor->getModule();
-	if ( $module->mustBePosted() ) {
-		$items[] = "action=" . $wgRequest->getVal( 'action' );
+	if ( $processor ) {
+		$module = $processor->getModule();
+		if ( $module->mustBePosted() ) {
+			$items[] = "action=" . $wgRequest->getVal( 'action' );
+		} else {
+			$items[] = wfArrayToCgi( $wgRequest->getValues() );
+		}
 	} else {
-		$items[] = wfArrayToCgi( $wgRequest->getValues() );
+		$items[] = "failed in ApiBeforeMain";
 	}
 	wfErrorLog( implode( ',', $items ) . "\n", $wgAPIRequestLog );
 	wfDebug( "Logged API request to $wgAPIRequestLog\n" );
diff --git a/includes/api/ApiMain.php b/includes/api/ApiMain.php
index eb24a35b868..8f270dcb18a 100644
--- a/includes/api/ApiMain.php
+++ b/includes/api/ApiMain.php
@@ -363,37 +363,7 @@ class ApiMain extends ApiBase {
 		try {
 			$this->executeAction();
 		} catch ( Exception $e ) {
-			// Allow extra cleanup and logging
-			wfRunHooks( 'ApiMain::onException', array( $this, $e ) );
-
-			// Log it
-			if ( !( $e instanceof UsageException ) ) {
-				MWExceptionHandler::logException( $e );
-			}
-
-			// Handle any kind of exception by outputting properly formatted error message.
-			// If this fails, an unhandled exception should be thrown so that global error
-			// handler will process and log it.
-
-			$errCode = $this->substituteResultWithError( $e );
-
-			// Error results should not be cached
-			$this->setCacheMode( 'private' );
-
-			$response = $this->getRequest()->response();
-			$headerStr = 'MediaWiki-API-Error: ' . $errCode;
-			if ( $e->getCode() === 0 ) {
-				$response->header( $headerStr );
-			} else {
-				$response->header( $headerStr, true, $e->getCode() );
-			}
-
-			// Reset and print just the error message
-			ob_clean();
-
-			// If the error occurred during printing, do a printer->profileOut()
-			$this->mPrinter->safeProfileOut();
-			$this->printResult( true );
+			$this->handleException( $e );
 		}
 
 		// Log the request whether or not there was an error
@@ -410,6 +380,73 @@ class ApiMain extends ApiBase {
 		ob_end_flush();
 	}
 
+	/**
+	 * Handle an exception as an API response
+	 *
+	 * @since 1.23
+	 * @param Exception $e
+	 */
+	protected function handleException( Exception $e ) {
+		// Allow extra cleanup and logging
+		wfRunHooks( 'ApiMain::onException', array( $this, $e ) );
+
+		// Log it
+		if ( !( $e instanceof UsageException ) ) {
+			MWExceptionHandler::logException( $e );
+		}
+
+		// Handle any kind of exception by outputting properly formatted error message.
+		// If this fails, an unhandled exception should be thrown so that global error
+		// handler will process and log it.
+
+		$errCode = $this->substituteResultWithError( $e );
+
+		// Error results should not be cached
+		$this->setCacheMode( 'private' );
+
+		$response = $this->getRequest()->response();
+		$headerStr = 'MediaWiki-API-Error: ' . $errCode;
+		if ( $e->getCode() === 0 ) {
+			$response->header( $headerStr );
+		} else {
+			$response->header( $headerStr, true, $e->getCode() );
+		}
+
+		// Reset and print just the error message
+		ob_clean();
+
+		// If the error occurred during printing, do a printer->profileOut()
+		$this->mPrinter->safeProfileOut();
+		$this->printResult( true );
+	}
+
+	/**
+	 * Handle an exception from the ApiBeforeMain hook.
+	 *
+	 * This tries to print the exception as an API response, to be more
+	 * friendly to clients. If it fails, it will rethrow the exception.
+	 *
+	 * @since 1.23
+	 * @param Exception $e
+	 */
+	public static function handleApiBeforeMainException( Exception $e ) {
+		ob_start();
+
+		try {
+			$main = new self( RequestContext::getMain(), false );
+			$main->handleException( $e );
+		} catch ( Exception $e2 ) {
+			// Nope, even that didn't work. Punt.
+			throw $e;
+		}
+
+		// Log the request and reset cache headers
+		$main->logRequest( 0 );
+		$main->sendCacheHeaders();
+
+		ob_end_flush();
+	}
+
 	/**
 	 * Check the &origin= query parameter against the Origin: HTTP header and respond appropriately.
 	 *