diff --git a/git-build.sh b/git-build.sh
index bbeecc0..3881f34 100755
--- a/git-build.sh
+++ b/git-build.sh
@@ -36,8 +36,20 @@ PROJECTS=()
 for arg in "$@"; do
 	if [[ "$arg" = "-f" ]] || [[ "$arg" = "--force" ]]; then
 		FORCE=1
+    # Maybe it's a task name and we find a corresponding source?
 	elif [ -f $BASEDIR/$arg.source ]; then
 		PROJECTS+=("$arg")
+    # Maybe it's a repo URL and we find a corresponding task?
+    elif matches="$(grep --files-with-matches --word-regexp "$arg" $BASEDIR/*.source)"; then
+        # Iterate over the files found to extract the task name
+        IFS= echo "$matches" | while read -r file; do
+            task_name="$(basename "$file" .source)"
+            # Make sure we don't have a .source file without name lying around, just in case
+            [[ "$task_name" != "" ]] && PROJECT+=("$task_name")
+        done
+    else
+        echo "ERROR: Unknown argument '$arg' (doesn't match a task name or source URL)"
+        exit 1
 	fi
 done