diff --git a/runtime/layers/fpm-dev/Dockerfile b/runtime/layers/fpm-dev/Dockerfile
index 842d340ba..ca25646eb 100644
--- a/runtime/layers/fpm-dev/Dockerfile
+++ b/runtime/layers/fpm-dev/Dockerfile
@@ -4,8 +4,8 @@ FROM bref/build-php-$PHP_VERSION as build_extensions
 # Re-expose the arg again inside this "FROM" block
 ARG PHP_VERSION
 
-RUN if [ "$PHP_VERSION" -ne "73" ]; then pecl install xdebug; fi
-RUN if [ "$PHP_VERSION" -eq "73" ]; then pecl install xdebug-3.1.6; fi
+RUN if [[ "$PHP_VERSION" != 7* ]]; then pecl install xdebug; fi
+RUN if [[ "$PHP_VERSION" == 7* ]]; then pecl install xdebug-3.1.6; fi
 RUN cp $(php -r "echo ini_get('extension_dir');")/xdebug.so /tmp
 
 RUN version=$(php -r "echo PHP_MAJOR_VERSION.PHP_MINOR_VERSION;") \