diff --git a/smol/parse.py b/smol/parse.py
index a078c1e..7786f38 100644
--- a/smol/parse.py
+++ b/smol/parse.py
@@ -169,7 +169,7 @@ def list_symbols(readelf_bin, lib):
         if vis != "DEFAULT" or ndx == "UND":
             continue
 
-        # strip away GNU versions
+        # strip away GLIBC versions
         symbol = re.sub(r"@@.*$", "", symbol)
         symbols.append(symbol)
 
@@ -182,7 +182,7 @@ def build_symbol_map(readelf_bin, libraries):
         symbols = list_symbols(readelf_bin, lib)
         for symbol in symbols:
             if symbol not in symbol_map:
-                symbol_map[symbol] = []
+                symbol_map[symbol] = set()
             soname = lib.split("/")[-1]
-            symbol_map[symbol].append(soname)
+            symbol_map[symbol].add(soname)
     return symbol_map
diff --git a/smold.py b/smold.py
index ab39688..6235fbe 100755
--- a/smold.py
+++ b/smold.py
@@ -177,7 +177,7 @@ def main():
             libs_for_symbol = libs_symbol_map[symbol]
             if len(libs_for_symbol) > 1:
                 error("E: the symbol '" + symbol + "' is provided by more than one library: " + str(libs_for_symbol))
-            library = libs_for_symbol[0]
+            library = libs_for_symbol.pop()
             symbols.setdefault(library, [])
             symbols[library].append((symbol, reloc))