diff --git a/contrib/plugins/uftrace_symbols.py b/contrib/plugins/uftrace_symbols.py
index 6eb999bca5..9f0095e73b 100755
--- a/contrib/plugins/uftrace_symbols.py
+++ b/contrib/plugins/uftrace_symbols.py
@@ -70,7 +70,10 @@ def find_symbols_locations(elf_file, symbols):
         file, line = out[i].split(':')
         # addr2line may return 'line (discriminator [0-9]+)' sometimes,
         # remove this to keep only line number.
-        line = line.split(' ')[0]
+        if line == '?':
+            line = 0
+        else:
+            line = int(line.split(' ')[0])
         s.set_loc(file, line)
 
 class BinaryFile: