diff --git a/src/git_flow/command/merge.py b/src/git_flow/command/merge.py
index 9c05184..6539bde 100644
--- a/src/git_flow/command/merge.py
+++ b/src/git_flow/command/merge.py
@@ -79,7 +79,9 @@ def check_merge_conflicts(target: str):
         print="Realizando merge de prueba para verificar conflictos"
     )
 
-    Git("merge", abort=True).exec(print="Abortando merge de prueba", check=False)
+    # Si el merge no llegó a realizarse (por ejemplo, "Already up to date") no hay nada que abortar
+    if Git.is_merging():
+        Git("merge", abort=True).exec(print="Abortando merge de prueba")
 
     if merge_conflicts:
         base.io_error(
diff --git a/src/git_flow/git.py b/src/git_flow/git.py
index 9f754e8..d54965c 100644
--- a/src/git_flow/git.py
+++ b/src/git_flow/git.py
@@ -63,6 +63,11 @@ class Git:
     def get_branches(prefix: str = ""):
         return Git._get_references("heads/" + prefix)
 
+    @staticmethod
+    def is_merging() -> bool:
+        """Indica si hay un merge en curso (existe MERGE_HEAD), con o sin conflictos."""
+        return Git("rev-parse", "MERGE_HEAD", quiet=True, verify=True).code() == 0
+
     @staticmethod
     def status():
         return list(map(Git.Status, Git("status", porcelain=True).lines(False)))