diff --git a/src/core/manager.c b/src/core/manager.c
index c36a954e61..f6c88ba114 100644
--- a/src/core/manager.c
+++ b/src/core/manager.c
@@ -1074,6 +1074,20 @@ static void unit_gc_sweep(Unit *u, unsigned gc_marker) {
                         is_bad = false;
         }
 
+        if (u->refs_by_target) {
+                const UnitRef *ref;
+
+                LIST_FOREACH(refs_by_target, ref, u->refs_by_target) {
+                        unit_gc_sweep(ref->source, gc_marker);
+
+                        if (ref->source->gc_marker == gc_marker + GC_OFFSET_GOOD)
+                                goto good;
+
+                        if (ref->source->gc_marker != gc_marker + GC_OFFSET_BAD)
+                                is_bad = false;
+                }
+        }
+
         if (is_bad)
                 goto bad;
 
diff --git a/src/core/unit.c b/src/core/unit.c
index 761ce40f2a..0330ae51fd 100644
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -344,7 +344,11 @@ bool unit_may_gc(Unit *u) {
 
         /* Checks whether the unit is ready to be unloaded for garbage collection.
          * Returns true when the unit may be collected, and false if there's some
-         * reason to keep it loaded. */
+         * reason to keep it loaded.
+         *
+         * References from other units are *not* checked here. Instead, this is done
+         * in unit_gc_sweep(), but using markers to properly collect dependency loops.
+         */
 
         if (u->job)
                 return false;
@@ -362,9 +366,6 @@ bool unit_may_gc(Unit *u) {
         if (u->perpetual)
                 return false;
 
-        if (u->refs_by_target)
-                return false;
-
         if (sd_bus_track_count(u->bus_track) > 0)
                 return false;