diff --git a/meson.build b/meson.build
index 759e50fcc..2607c5c8f 100644
--- a/meson.build
+++ b/meson.build
@@ -81,7 +81,8 @@ common_flags = [
   '-Wsign-compare',
   '-Wpointer-arith',
   '-Wpointer-sign',
-  '-Wformat',
+  '-Werror=format',
+  '-Wno-error=format-overflow', # avoid some "‘%s’ directive argument is null"
   '-Wformat-security',
   '-Wimplicit-fallthrough',
   '-Wmissing-braces',
diff --git a/spa/plugins/libcamera/libcamera-utils.cpp b/spa/plugins/libcamera/libcamera-utils.cpp
index fdfd6e46d..7cbe565c6 100644
--- a/spa/plugins/libcamera/libcamera-utils.cpp
+++ b/spa/plugins/libcamera/libcamera-utils.cpp
@@ -807,7 +807,7 @@ mmap_init(struct impl *impl, struct port *port,
 			    port->memtype == SPA_DATA_MemFd) {
 				d[j].flags |= SPA_DATA_FLAG_MAPPABLE;
 				d[j].fd = bufs[i]->planes()[j].fd.get();
-				spa_log_debug(impl->log, "Got fd = %ld for buffer: #%d", d[j].fd, i);
+				spa_log_debug(impl->log, "Got fd = %" PRId64 " for buffer: #%d", d[j].fd, i);
 				d[j].data = NULL;
 				SPA_FLAG_SET(b->flags, BUFFER_FLAG_ALLOCATED);
 			}
diff --git a/src/modules/module-pulse-tunnel.c b/src/modules/module-pulse-tunnel.c
index 37b6f6d56..3e1592040 100644
--- a/src/modules/module-pulse-tunnel.c
+++ b/src/modules/module-pulse-tunnel.c
@@ -750,7 +750,7 @@ static void stream_latency_update_cb(pa_stream *s, void *userdata)
 	pa_usec_t usec;
 	int negative;
 	pa_stream_get_latency(s, &usec, &negative);
-	pw_log_debug("latency %ld negative %d", usec, negative);
+	pw_log_debug("latency %" PRIu64 " negative %d", usec, negative);
 }
 
 static int create_pulse_stream(struct impl *impl)