diff --git a/2.4/Dockerfile b/2.4/Dockerfile
index e029e9b..5b560a9 100644
--- a/2.4/Dockerfile
+++ b/2.4/Dockerfile
@@ -158,7 +158,7 @@ RUN set -eux; \
 	httpd -v
 
 # https://httpd.apache.org/docs/2.4/stopping.html#gracefulstop
-STOPSIGNAL WINCH
+STOPSIGNAL SIGWINCH
 
 COPY httpd-foreground /usr/local/bin/
 
diff --git a/2.4/alpine/Dockerfile b/2.4/alpine/Dockerfile
index 672a54a..ae208a2 100644
--- a/2.4/alpine/Dockerfile
+++ b/2.4/alpine/Dockerfile
@@ -149,7 +149,7 @@ RUN set -eux; \
 	httpd -v
 
 # https://httpd.apache.org/docs/2.4/stopping.html#gracefulstop
-STOPSIGNAL WINCH
+STOPSIGNAL SIGWINCH
 
 COPY httpd-foreground /usr/local/bin/