diff --git a/fuzzers/005-tilegrid/Makefile b/fuzzers/005-tilegrid/Makefile
index 93dacc98..800b2ba6 100644
--- a/fuzzers/005-tilegrid/Makefile
+++ b/fuzzers/005-tilegrid/Makefile
@@ -72,7 +72,12 @@ endif
 ifeq (${HAS_HIGH_PERFORMANCE_BANKS}, 1)
 TILEGRID_TDB_DEPENDENCIES += iob18/$(BUILD_FOLDER)/segbits_tilegrid.tdb
 TILEGRID_TDB_DEPENDENCIES += iob18_int/$(BUILD_FOLDER)/segbits_tilegrid.tdb
-TILEGRID_TDB_DEPENDENCIES += iob18_sing/$(BUILD_FOLDER)/segbits_tilegrid.tdb
+# iob18_sing is intentionally NOT a tilegrid dependency: SING tiles inherit
+# their base address from the parent IOB18 column via propagate_IOB_SING in
+# generate_full.py, not via direct measurement. The iob18_sing rule below is
+# kept so the build can still be invoked manually as a Vivado-measurement
+# guard (its tdb half-aligns at offset+1 - exactly what propagate_IOB_SING's
+# top-tile alias models with offset=99).
 TILEGRID_TDB_DEPENDENCIES += ioi18/$(BUILD_FOLDER)/segbits_tilegrid.tdb
 # GTX transceiver fuzzers. Kintex-7 only: the xc7vx485t-ffg1761 package used for
 # virtex7 bonds only ~7 of its 14 GTX quads, so the unbonded GTX_COMMON tiles
diff --git a/fuzzers/005-tilegrid/generate_full.py b/fuzzers/005-tilegrid/generate_full.py
index cec07ddf..fe3355bf 100644
--- a/fuzzers/005-tilegrid/generate_full.py
+++ b/fuzzers/005-tilegrid/generate_full.py
@@ -369,7 +369,8 @@ def propagate_IOB_SING(database, tiles_by_grid):
         if tile in seen_iobs:
             continue
 
-        if database[tile]["type"] not in ["LIOB33", "RIOB33", "RIOB18"]:
+        if database[tile]["type"] not in ["LIOB33", "RIOB33", "LIOB18",
+                                          "RIOB18"]:
             continue
 
         while True:
@@ -439,7 +440,7 @@ def propagate_IOI_SING(database, tiles_by_grid):
         if tile in seen_iois:
             continue
 
-        if database[tile]["type"] not in ["LIOI3", "RIOI3", "RIOI"]:
+        if database[tile]["type"] not in ["LIOI3", "RIOI3", "LIOI", "RIOI"]:
             continue
 
         while True: