diff --git a/src/libstore/store-api.cc b/src/libstore/store-api.cc
index a2095e02e..0b78f999e 100644
--- a/src/libstore/store-api.cc
+++ b/src/libstore/store-api.cc
@@ -171,7 +171,7 @@ std::pair<StorePath, Hash> StoreDirConfig::computeStorePath(
 {
     auto [h, size] = hashPath(path, method.getFileIngestionMethod(), hashAlgo, filter);
     if (size && *size >= settings.largePathWarningThreshold)
-        warn("hashed large path '%s' (%d bytes)", path, *size);
+        warn("hashed large path '%s' (%s)", path, renderSize(*size));
     return {
         makeFixedOutputPathFromCA(
             name,
@@ -215,7 +215,7 @@ StorePath Store::addToStore(
     LengthSource lengthSource(*source);
     auto storePath = addToStoreFromDump(lengthSource, name, fsm, method, hashAlgo, references, repair);
     if (lengthSource.total >= settings.largePathWarningThreshold)
-        warn("copied large path '%s' to the store (%d bytes)", path, lengthSource.total);
+        warn("copied large path '%s' to the store (%s)", path, renderSize(lengthSource.total));
     return storePath;
 }
 
diff --git a/src/libutil/util.cc b/src/libutil/util.cc
index f893fc12d..16bca093c 100644
--- a/src/libutil/util.cc
+++ b/src/libutil/util.cc
@@ -112,7 +112,7 @@ std::string rewriteStrings(std::string s, const StringMap & rewrites)
 }
 
 
-std::string renderSize(uint64_t value)
+std::string renderSize(uint64_t value, bool align)
 {
     static const std::array<char, 9> prefixes{{
         'K', 'K', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y'
@@ -123,7 +123,7 @@ std::string renderSize(uint64_t value)
         ++power;
         res /= 1024;
     }
-    return fmt("%6.1f %ciB", power == 0 ? res / 1024 : res, prefixes.at(power));
+    return fmt(align ? "%6.1f %ciB" : "%.1f %ciB", power == 0 ? res / 1024 : res, prefixes.at(power));
 }
 
 
diff --git a/src/libutil/util.hh b/src/libutil/util.hh
index 01e42ce57..0c8c82bfd 100644
--- a/src/libutil/util.hh
+++ b/src/libutil/util.hh
@@ -139,9 +139,10 @@ N string2IntWithUnitPrefix(std::string_view s)
 
 /**
  * Pretty-print a byte value, e.g. 12433615056 is rendered as `11.6
- * GiB`.
+ * GiB`. If `align` is set, the number will be right-justified
+ * (e.g. `__11.6 GiB`).
  */
-std::string renderSize(uint64_t value);
+std::string renderSize(uint64_t value, bool align = false);
 
 /**
  * Parse a string into a float.
diff --git a/src/nix/path-info.cc b/src/nix/path-info.cc
index a1a2c40f4..47f9baee5 100644
--- a/src/nix/path-info.cc
+++ b/src/nix/path-info.cc
@@ -140,7 +140,7 @@ struct CmdPathInfo : StorePathsCommand, MixJSON
     void printSize(uint64_t value)
     {
         if (humanReadable)
-            std::cout << fmt("\t%s", renderSize(value));
+            std::cout << fmt("\t%s", renderSize(value, true));
         else
             std::cout << fmt("\t%11d", value);
     }