diff --git a/scripts/compare-llama-bench.py b/scripts/compare-llama-bench.py
index 239c458d8..6205fe88d 100755
--- a/scripts/compare-llama-bench.py
+++ b/scripts/compare-llama-bench.py
@@ -124,9 +124,22 @@ if input_file is None:
 
 connection = sqlite3.connect(input_file)
 cursor = connection.cursor()
-builds = cursor.execute("SELECT DISTINCT build_commit FROM test;").fetchall()
 
-commit_short_len = len(builds[0][0])
+build_len_min: int = cursor.execute("SELECT MIN(LENGTH(build_commit)) from test;").fetchone()[0]
+build_len_max: int = cursor.execute("SELECT MAX(LENGTH(build_commit)) from test;").fetchone()[0]
+
+if build_len_min != build_len_max:
+    logger.warning(f"{input_file} contains commit hashes of differing lengths. It's possible that the wrong commits will be compared. "
+                   "Try purging the the database of old commits.")
+    cursor.execute(f"UPDATE test SET build_commit = SUBSTRING(build_commit, 1, {build_len_min});")
+
+build_len: int = build_len_min
+
+builds = cursor.execute("SELECT DISTINCT build_commit FROM test;").fetchall()
+builds = list(map(lambda b: b[0], builds))  # list[tuple[str]] -> list[str]
+
+if not builds:
+    raise RuntimeError(f"{input_file} does not contain any builds.")
 
 try:
     repo = git.Repo(".", search_parent_directories=True)
@@ -140,11 +153,11 @@ def find_parent_in_data(commit: git.Commit):
     seen_hexsha8 = set()
     while heap:
         depth, current_commit = heapq.heappop(heap)
-        current_hexsha8 = commit.hexsha[:commit_short_len]
-        if (current_hexsha8,) in builds:
+        current_hexsha8 = commit.hexsha[:build_len]
+        if current_hexsha8 in builds:
             return current_hexsha8
         for parent in commit.parents:
-            parent_hexsha8 = parent.hexsha[:commit_short_len]
+            parent_hexsha8 = parent.hexsha[:build_len]
             if parent_hexsha8 not in seen_hexsha8:
                 seen_hexsha8.add(parent_hexsha8)
                 heapq.heappush(heap, (depth + 1, parent))
@@ -158,40 +171,40 @@ def get_all_parent_hexsha8s(commit: git.Commit):
 
     while unvisited:
         current_commit = unvisited.pop(0)
-        visited.append(current_commit.hexsha[:commit_short_len])
+        visited.append(current_commit.hexsha[:build_len])
         for parent in current_commit.parents:
-            if parent.hexsha[:commit_short_len] not in visited:
+            if parent.hexsha[:build_len] not in visited:
                 unvisited.append(parent)
 
     return visited
 
 
-def get_commit_name(hexsha8):
+def get_commit_name(hexsha8: str):
     """Helper function to find a human-readable name for a commit if possible."""
     if repo is None:
         return hexsha8
     for h in repo.heads:
-        if h.commit.hexsha[:commit_short_len] == hexsha8:
+        if h.commit.hexsha[:build_len] == hexsha8:
             return h.name
     for t in repo.tags:
-        if t.commit.hexsha[:commit_short_len] == hexsha8:
+        if t.commit.hexsha[:build_len] == hexsha8:
             return t.name
     return hexsha8
 
 
-def get_commit_hexsha8(name):
+def get_commit_hexsha8(name: str):
     """Helper function to search for a commit given a human-readable name."""
     if repo is None:
         return None
     for h in repo.heads:
         if h.name == name:
-            return h.commit.hexsha[:commit_short_len]
+            return h.commit.hexsha[:build_len]
     for t in repo.tags:
         if t.name == name:
-            return t.commit.hexsha[:commit_short_len]
+            return t.commit.hexsha[:build_len]
     for c in repo.iter_commits("--all"):
-        if c.hexsha[:commit_short_len] == name[:commit_short_len]:
-            return c.hexsha[:commit_short_len]
+        if c.hexsha[:build_len] == name[:build_len]:
+            return c.hexsha[:build_len]
     return None
 
 
@@ -199,7 +212,7 @@ hexsha8_baseline = name_baseline = None
 
 # If the user specified a baseline, try to find a commit for it:
 if known_args.baseline is not None:
-    if (known_args.baseline,) in builds:
+    if known_args.baseline in builds:
         hexsha8_baseline = known_args.baseline
     if hexsha8_baseline is None:
         hexsha8_baseline = get_commit_hexsha8(known_args.baseline)
@@ -228,7 +241,7 @@ hexsha8_compare = name_compare = None
 
 # If the user has specified a compare value, try to find a corresponding commit:
 if known_args.compare is not None:
-    if (known_args.compare,) in builds:
+    if known_args.compare in builds:
         hexsha8_compare = known_args.compare
     if hexsha8_compare is None:
         hexsha8_compare = get_commit_hexsha8(known_args.compare)