diff --git a/Debian/Dockerfile.template b/Debian/Dockerfile.template
index 7803c384..91304355 100644
--- a/Debian/Dockerfile.template
+++ b/Debian/Dockerfile.template
@@ -31,6 +31,11 @@ COPY requirements.txt /
 # Install additional extensions
 RUN set -xe; \
 	apt-get update; \
+	if apt list --upgradable 2>/dev/null | grep -q '^postgres'; then \
+		echo "ERROR: Upgradable postgres packages found!"; \
+		apt list --upgradable 2>/dev/null | grep '^postgres'; \
+		exit 1; \
+	fi; \
 	apt-get install -y --no-install-recommends \
 		"postgresql-${PG_MAJOR}-pgaudit" \
 		"postgresql-${PG_MAJOR}-pgvector" \