diff --git a/src/shared/specifier.c b/src/shared/specifier.c
index c4a3ffd18c..a602413cd5 100644
--- a/src/shared/specifier.c
+++ b/src/shared/specifier.c
@@ -102,11 +102,18 @@ int specifier_printf(const char *text, const Specifier table[], void *userdata,
                 else
                         *(t++) = *f;
 
-        /* if string ended with a stray %, also end with % */
+        /* If string ended with a stray %, also end with % */
         if (percent)
                 *(t++) = '%';
+        *(t++) = 0;
+
+        /* Try to deallocate unused bytes, but don't sweat it too much */
+        if ((size_t)(t - ret) < allocated) {
+                t = realloc(ret, t - ret);
+                if (t)
+                        ret = t;
+        }
 
-        *t = 0;
         *_ret = TAKE_PTR(ret);
         return 0;
 }