diff --git a/CHANGELOG.md b/CHANGELOG.md
index 784e95222..16e6f6926 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -36,6 +36,13 @@ these packages. All five distributions share one version and one entry.
   value that cannot be read as its type, such as a `run_mode` that is not
   text, is refused with `INVALID_REQUEST` before sending, where a NIM
   answered `422 VALIDATION_FAILED`.
+- The `duckdb` extra holds `duckdb` below 2. The 2.0 release warns on the
+  Arrow fetch the relational engine reads DuckDB tables through, and this
+  release is tested against 1.5.
+- `structured-data-models-client` and the relational engine hold `pandas`
+  below 3.1. The 3.1 release raises taking a date offset from the earliest
+  timestamp, which the engine does for every graph without a time column,
+  and this release is tested against 3.0.
 
 ### Fixed
 
diff --git a/packages/structured-data-models-client/pyproject.toml b/packages/structured-data-models-client/pyproject.toml
index 9dfbb274b..42c700625 100644
--- a/packages/structured-data-models-client/pyproject.toml
+++ b/packages/structured-data-models-client/pyproject.toml
@@ -41,7 +41,10 @@ classifiers = [
 dependencies = [
     "structured-data-models-api==1.0.0",
     "structured-data-models-pql==1.0.0",
-    "pandas>=2.2.2",
+    # 3.1 builds a frame around an integer past the float range where earlier
+    # releases refused one, and a request's description relies on that
+    # refusal to leave out the table carrying it.
+    "pandas>=2.2.2,<3.1",
     "numpy>=1.23",
     "requests>=2.28",
     "urllib3>=1.26",
diff --git a/packages/structured-data-models-connectors/pyproject.toml b/packages/structured-data-models-connectors/pyproject.toml
index b96d010d4..6bce18c6a 100644
--- a/packages/structured-data-models-connectors/pyproject.toml
+++ b/packages/structured-data-models-connectors/pyproject.toml
@@ -61,7 +61,10 @@ sqlite = [
     "adbc-driver-sqlite",
 ]
 duckdb = [
-    "duckdb>=1.5.0",
+    # 2.0 warns on an Arrow fetch from a DB-API cursor, which the engine
+    # makes for every table and sample it reads. Lifting this moves those
+    # reads off the cursor.
+    "duckdb>=1.5.0,<2",
 ]
 snowflake = [
     # 5.0 empties `DEFAULT_CONFIGURATION` and rewrites keyword names through
diff --git a/packages/structured-data-models-relational-engine/setup.py b/packages/structured-data-models-relational-engine/setup.py
index 0f289c9a9..65c1aa3a5 100644
--- a/packages/structured-data-models-relational-engine/setup.py
+++ b/packages/structured-data-models-relational-engine/setup.py
@@ -39,7 +39,9 @@
 setup(
     install_requires=[
         'numpy',
-        'pandas',
+        # 3.1 raises taking a `DateOffset` from `Timestamp.min`, which is the
+        # anchor time of every graph without a time column.
+        'pandas<3.1',
         # The warehouse backends read results as `pd.ArrowDtype`, which pandas
         # refuses below pyarrow 10.0.1. Databricks Runtime 14.3 LTS and
         # serverless environment 1 ship pyarrow 8, and failed there on import.
diff --git a/uv.lock b/uv.lock
index be6a79353..ba3219cb0 100644
--- a/uv.lock
+++ b/uv.lock
@@ -3166,7 +3166,7 @@ test = [
 requires-dist = [
     { name = "databricks-sdk", marker = "extra == 'databricks-serving'", specifier = ">=0.68.0,<1.0" },
     { name = "numpy", specifier = ">=1.23" },
-    { name = "pandas", specifier = ">=2.2.2" },
+    { name = "pandas", specifier = ">=2.2.2,<3.1" },
     { name = "pytest", marker = "extra == 'test'" },
     { name = "requests", specifier = ">=2.28" },
     { name = "requests-mock", marker = "extra == 'test'" },
@@ -3241,7 +3241,7 @@ requires-dist = [
     { name = "databricks-sdk", marker = "extra == 'databricks'", specifier = ">=0.89,<1.0" },
     { name = "databricks-sdk", marker = "extra == 'lakebase'", specifier = ">=0.89,<1.0" },
     { name = "databricks-sql-connector", marker = "extra == 'databricks'", specifier = ">=4.1.3" },
-    { name = "duckdb", marker = "extra == 'duckdb'", specifier = ">=1.5.0" },
+    { name = "duckdb", marker = "extra == 'duckdb'", specifier = ">=1.5.0,<2" },
     { name = "moto", extras = ["server"], marker = "extra == 'test'", specifier = ">=5" },
     { name = "pandas", specifier = ">=2.2.2" },
     { name = "psycopg", marker = "extra == 'lakebase'", specifier = ">=3.1" },
@@ -3348,7 +3348,7 @@ requires-dist = [
     { name = "numpy" },
     { name = "openai", marker = "extra == 'explain'", specifier = ">=1.40" },
     { name = "packaging", marker = "extra == 'test'" },
-    { name = "pandas" },
+    { name = "pandas", specifier = "<3.1" },
     { name = "pooch", marker = "extra == 'relbench'" },
     { name = "pooch", marker = "extra == 'test'" },
     { name = "pyarrow", specifier = ">=10.0.1" },