diff --git a/png.c b/png.c
index 13274ee57..4cf592334 100644
--- a/png.c
+++ b/png.c
@@ -178,38 +178,39 @@ png_user_version_check(png_structrp png_ptr, png_const_charp user_png_ver)
       do
       {
          i++;
-         if (user_png_ver[i] != png_libpng_ver[i])
+         if (user_png_ver[i] != PNG_LIBPNG_VER_STRING[i])
             png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
          if (user_png_ver[i] == '.')
             found_dots++;
-      } while (found_dots < 2 && png_libpng_ver[i] != 0 && user_png_ver[i] != 0);
+      } while (found_dots < 2 && user_png_ver[i] != 0 &&
+            PNG_LIBPNG_VER_STRING[i] != 0);
    }
 
    else
       png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
 
    if ((png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH) != 0)
-      {
+   {
 #ifdef PNG_WARNINGS_SUPPORTED
-         size_t pos = 0;
-         char m[128];
+      size_t pos = 0;
+      char m[128];
 
-         pos = png_safecat(m, (sizeof m), pos,
-             "Application built with libpng-");
-         pos = png_safecat(m, (sizeof m), pos, user_png_ver);
-         pos = png_safecat(m, (sizeof m), pos, " but running with ");
-         pos = png_safecat(m, (sizeof m), pos, png_libpng_ver);
-         PNG_UNUSED(pos)
+      pos = png_safecat(m, (sizeof m), pos,
+          "Application built with libpng-");
+      pos = png_safecat(m, (sizeof m), pos, user_png_ver);
+      pos = png_safecat(m, (sizeof m), pos, " but running with ");
+      pos = png_safecat(m, (sizeof m), pos, PNG_LIBPNG_VER_STRING);
+      PNG_UNUSED(pos)
 
-         png_warning(png_ptr, m);
+      png_warning(png_ptr, m);
 #endif
 
 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
-         png_ptr->flags = 0;
+      png_ptr->flags = 0;
 #endif
 
-         return 0;
-      }
+      return 0;
+   }
 
    /* Success return. */
    return 1;