diff --git a/pyproject.toml b/pyproject.toml
index 5f4aded..b3d567b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "slocum-glide"
-version = "0.1.2"
+version = "0.1.3"
 description = "Process Slocum glider data"
 readme = "README.md"
 authors = [
diff --git a/src/glide/process_l1.py b/src/glide/process_l1.py
index f2853ab..ac195ab 100644
--- a/src/glide/process_l1.py
+++ b/src/glide/process_l1.py
@@ -316,6 +316,15 @@ def merge(
             _log.debug("Skipping %s; QC flags are re-initialized after merge", v)
             continue
 
+        if v in ds.data_vars:
+            _log.warning(
+                "Variable %s is present in both flight and science files; "
+                "keeping the %s version",
+                v,
+                times_from,
+            )
+            continue
+
         try:  # Only drop variables if the flag is explicitly set
             drop = config["variables"][v]["drop_from_l2"]
             if drop:
diff --git a/uv.lock b/uv.lock
index e3b611a..a7a72ff 100644
--- a/uv.lock
+++ b/uv.lock
@@ -1951,7 +1951,7 @@ wheels = [
 
 [[package]]
 name = "slocum-glide"
-version = "0.1.2"
+version = "0.1.3"
 source = { editable = "." }
 dependencies = [
     { name = "bottleneck" },