diff --git a/tools/mockup.sh b/tools/mockup.sh
index 448c99741..9a9a49f26 100755
--- a/tools/mockup.sh
+++ b/tools/mockup.sh
@@ -15,7 +15,9 @@ if [ $# -eq 0 ]; then
 fi
 
 for SYMBOL; do
-    WHERE=$(grep -nH "^[a-zA-Z0-9_ (),]* [*]*$SYMBOL(" */*.h )
+    # If there are multiple declarations, pick first (eg. common/memleak.h
+    # has notleak_ as a declaration, and then an inline).
+    WHERE=$(grep -nH "^[a-zA-Z0-9_ (),]* [*]*$SYMBOL(" */*.h | head -n1)
     if [ x"$WHERE" != x ]; then
 	STUB='\n{ fprintf(stderr, "'$SYMBOL' called!\\n"); abort(); }'
     else